An incident on April 12, 2026, has reignited diplomatic and security tensions in the Amazon border region between Colombia and Peru, following an exchange of gunfire between a Colombian civilian vessel and the Marina de Guerra del Perú, a Peruvian Navy River unit, on the Putumayo River. The incident left one Colombian citizen dead and one person injured on each side.

The episode occurred near Marandúa (Amazonas, Colombia), across from the Peruvian town of El Estrecho. According to Colombia’s Defense Minister, Pedro Sánchez, the fatal victim was identified “as José Miguel Gutiérrez Baquero, owner of the cargo vessel involved in the incident, and one of his sons was injured,” while two other crew members were detained by Peruvian authorities.

Conflicting accounts of the operation

According to the Peruvian government statement, “the incident occurred during a patrol operation aimed at securing the electoral process,” previously coordinated between the two countries. Authorities said two Navy speedboats requested that the Colombian vessel stop for identification.

Peru’s Ministry of Foreign Affairs, which is leading the process, said that “the Colombian vessel refused to comply with the control order and opened fire on two Peruvian Navy units, which returned fire.” As a result, “a member of the Peruvian Navy was also injured, although he is out of danger.”

Colombian authorities, led by the Foreign Ministry, have requested a full clarification of the events and verification of the circumstances surrounding the exchange of gunfire.

Diplomatic channels activated

Following the incident, the governments of Colombia and Peru activated diplomatic and military channels. Colombia’s defense minister said that “preliminary measures were agreed, including prioritizing medical attention for the injured, facilitating the work of judicial authorities, and establishing a binational commission to investigate what happened.”

Colombia’s Foreign Ministry formally requested clarification of “the circumstances of time, mode and place” of the attack, while the Peruvian government expressed its “willingness to cooperate and maintain border coordination mechanisms.”

The detained individuals “remain in the custody of the Fiscalía Provincial Mixta de Putumayo, with access to consular assistance and due process guarantees.”

So far, no final responsibilities have been determined, and both countries agree on the need for a thorough investigation. Both governments said the issue will be addressed at the next High-Level Mechanism on Security and Judicial Cooperation meeting, scheduled for May 2026 in Bogotá.

Context of prior tensions

The incident comes amid sensitive bilateral relations. In recent months, Colombia and Peru have had disagreements over territorial issues in the Amazon, particularly regarding Santa Rosa de Loreto island.

The dispute dates back to August 5, 2025, when President Gustavo Petro said on X that the “government of Peru has taken over territory that belongs to Colombia” and alleged a “violation of the Rio de Janeiro Protocol, which defines the boundaries between the two countries.”

“The Rio de Janeiro Protocol established that the border is the deepest channel of the Amazon River and that any dispute must be resolved between the parties,” Petro said, referring to the emergence of new river islands “north of the current deepest channel,” which, according to his position, should belong to Colombia.

In response, Peru’s Foreign Ministry expressed its “strongest and most forceful protest,” stating that the island, home to about 3,000 residents, mostly Peruvians, is part of its territory and is key to regional river trade.

Tensions escalated days later when then-presidential pre-candidate Daniel Quintero traveled to the island and raised a Colombian flag during a campaign event broadcast on social media, saying: “I will not allow them to take the Amazon from us. Santa Rosa is Colombia.”

The Peruvian government described the act as an “unnecessary action” that “distracts from the cooperation efforts that Peru and Colombia must prioritize to jointly address urgent challenges.”

Headline photo: President Gustavo Petro, Vice President Francia Márquez and Defense Minister Pedro Sánchez at an event held in Leticia (Amazonas) to address tensions with Peru, Aug. 7, 2025. Photo courtesy of Colombia’s Ministry of Defense.

On Tuesday, President Petro alleged via the social media platform X that Peru had illegally claimed land belonging to Colombia. “Again, the government of Peru has taken over territory that belongs to Colombia and has violated the Rio de Janeiro Protocol,” Petro stated. “Islands have appeared that are north of the current deepest line, and the Government of Peru has just appropriated them by law and placed the capital of a municipality on land that, by the treaty, should belong to Colombia.”

Petro’s comments refer to the Peruvian Congress’s recent creation of the Santa Rosa de Loreto district, establishing its capital on Isla Santa Rosa. The Colombian president affirmed that his government “will use, first of all, diplomatic steps to defend national sovereignty.” He also announced the relocation of Colombia’s Battle of Boyacá commemoration to Leticia, the capital of its Amazonas department, as a direct response to the dispute.

Colombia’s President Gustavo Petro (left) has expressed an ideological affinity for disgraced Peruvian President Pedro Castillo (right).

The Peruvian Ministry of Foreign Affairs swiftly responded, expressing “its most firm and energetic protest” and rejecting Colombia’s claims. In a formal statement, the ministry asserted that the new district’s territory “is under the sovereignty and jurisdiction of our country, by the international political limits established” in the 1922 Boundary and Fluvial Navigation Treaty between Peru and Colombia and the subsequent work of the Joint Boundary Demarcation Commission.

Peruvian Congressman Alejandro Muñante of the Renovación Popular party suggested Petro’s motives were political. He urged his country’s foreign minister to “cut off any hidden intention of Mr. Petro to want to divert the focus of attention from the many problems his country has towards a conflict that he has invented.” Muñante added, “Mr. Petro has a not-so-peaceful background; he was a former guerrilla, he still considers himself a communist militant, so we are not talking about a person who is objective.”

In Colombia, opposition Senator and presidential pre-candidate Maria Fernanda Cabal criticized the Petro administration’s handling of the issue. “Don’t be irresponsible! You are mediocre people who understand nothing of what is happening in the country,” she posted on X. “They attack Peru, but allow the genocidal Maduro regime to take over Catatumbo. This is not resolved with threats.”

As both nations trade official communiqués and public statements, the call from academic experts to reactivate the binational border commission remains the most cited path toward a de-escalation of the conflict.

A History of Strained Relations Between Petro & Boluarte

This territorial flare-up is the latest in a series of diplomatic clashes between the governments of Gustavo Petro and Peruvian President Dina Boluarte. Relations soured significantly after the December 7, 2022, impeachment and arrest of former Peruvian President Pedro Castillo following his attempted “self-coup.”

President Petro, an ally of Castillo, has repeatedly defended the ousted leader and questioned the legitimacy of Boluarte’s succession. The diplomatic fallout led to the mutual withdrawal of ambassadors. On February 18, 2023, the Peruvian Congress declared President Petro persona non grata with a vote of 72 in favor, 29 against, and 7 abstentions. The motion expressed rejection of Petro’s “offensive” statements against Peru’s National Police (PNP) regarding their response to social mobilizations that supported the ousted Castillo.

A nearly identical dispute over Isla Santa Rosa arose in July 2024. At the time, a Colombian foreign ministry official stated the island “would not belong to Peru and would be irregularly occupied.” Peru issued a formal protest, and the incident was considered closed after Colombia offered a satisfactory response. The current escalation indicates the underlying issue was never resolved.

Dueling Interpretations of Treaties and Geography

The border between Colombia and Peru was largely defined by the Salomón-Lozano Treaty of March 24, 1922. “The river’s course was divided between the two States not by the middle, but by the best navigable channel, the deepest one,” explains Walter Arévalo, a professor of International Law at the Universidad del Rosario in Colombia. This principle is known as the thalweg.

According to historian Felipe Arias Escobar of the Pontificia Universidad Javeriana, the treaty was initially met with opposition in both nations, leading to the Colombia-Peru War of 1932. The conflict concluded with the signing of the Rio de Janeiro Protocol in 1934, which ratified the 1922 treaty. “It is a conflict in the service of nationalism that at the time served to strengthen national identity,” Arias Escobar notes.

The core of the conflict lies in differing interpretations of historical agreements and the dynamic geography of the Amazon River.

Colombia’s Position

The Colombian Foreign Ministry presented a more nuanced position than President Petro’s direct accusation of illegal occupation. The ministry stated that Isla Santa Rosa is a formation that emerged in the Amazon River after the only official allocation of islands between the two countries in 1929.

Rafael Orozco, Director of the Americas for the Colombian Foreign Ministry, clarified the stance: “For the island ‘Santa Rosa’ and others that have arisen after 1929, an allocation process must be carried out by common agreement between the Foreign Ministries.”

The Colombian government announced it has presented formal protest notes to Peru, requesting the reactivation of the Permanent Joint Commission for the Inspection of the Colombo-Peruvian Border (COMPERIF) “so that, based on an allocation methodology, a decision can be made on the sovereignty of the islands that have emerged in the course of the Amazon River after 1929.” The ministry’s statement emphasized, “For years, Colombia has maintained the need for binational work to be carried out for the allocation of islands and has reiterated the position that the ‘Isla de Santa Rosa’ has not been assigned to Peru.”

Castillo’s failed self-coup led to Dina Boluarte being recognized as Peru’s 1st female vice-president.

Peru’s Position

Peru counters that the island is not a new formation requiring allocation. Peruvian Foreign Minister Elmer Schialer stated that any claim of a border dispute is “a completely mistaken position from a legal, geographical, technical, and historical point of view.”

Schialer argues that Isla Santa Rosa was originally part of Isla Chinería, which was assigned to Peru in the 1929 demarcation. “One of the islands assigned to Peru was Chinería, and, around the 1950s, the river split off a part that was later called Santa Rosa Island. It was not born nor did it emerge, but was part of Chinería,” Schialer explained. He added that the channel that separated it later dried up, reintegrating it with the larger island. “Not only was Santa Rosa Peruvian, but it continues to be Peruvian.”

The Peruvian Foreign Ministry’s communiqué echoed this, stating, “The town of Santa Rosa is an integral part of the Peruvian island of Chinería, assigned to Peru in 1929.” Schialer stressed that Peru has developed infrastructure on the island since the 1970s, including a school and government offices, “without the Colombians ever saying anything.” He concluded, “Santa Rosa is Peruvian, just as Leticia is Colombian… We should not ask a friendly nation what we can or cannot do in our territory.”

View the disputed area on Google Maps.

Explore the region in Google Earth.

The Shifting River and the Fate of Leticia

Compounding the sovereignty dispute is a pressing environmental issue threatening Colombia’s primary Amazon port. Sedimentation, deforestation, and climate change are causing the main channel of the Amazon River to shift away from Leticia and towards Peruvian territory.

A study by the Faculty of Mines at the Universidad Nacional de Colombia warned that Colombia is at risk of losing its most significant fluvial connection. “A model developed by the National Navy anticipated several years ago that, by 2030, the Amazon River could cease to pass in front of Leticia for most of the year… Today, the model is a reality,” the study concluded. Professor Lilian Posada García, involved in the research, warned, “If immediate action is not taken, Leticia will cease to be a riverside city. The implications go beyond the symbolic; they are cultural, economic, and territorial.”

President Petro directly linked this environmental threat to the current dispute, expressing fear that Peru’s actions could “make Leticia disappear as an Amazonian port, taking away its commercial life.”

Experts like Santiago Duque, a limnology professor at the Universidad Nacional de Colombia, emphasize the river’s dynamic nature. “When the treaty was signed, opposite Leticia, there were only two islands… a border between Colombia and Peru is a living, changing border, which both countries must review from time to time.” He added, “It is time for the countries to sit down to review the new geographical situation and make decisions. There are more than seven new islands, including Santa Rosa.”

Headline image: Aerial view of Leticia, Colombia, Tabatinga, Brazil, and Santa Rosa Peru, on the Amazon River. Satellite image by Google Earth.