Months of tension between Colombia's leftist President Gustavo Petro and his right-wing Ecuadoran counterpart, Daniel Noboa, an ally of US President Donald Trump, spiked Monday when Petro alleged that explosives were dropped from a plane near the border.

On Tuesday, Petro posted on X a photo of an unexploded "bomb" that he said had fallen on the Colombian-Ecuadoran frontier. He called for a thorough investigation, saying: "It fell 100 meters from the home of a poor family."

Local farmers speaking with AFP corroborated Petro's account, amid escalating tension between the neighboring countries.

"We were all terrified -- you know, scared -- and worried that those devices might suddenly explode and take our lives," farmer Julian Imbacuan told AFP by phone.

Colombian Defense Minister Pedro Sanchez implored residents to avoid the area.

Noboa took to X Tuesday to retort that Ecuador is "currently bombing locations that served as hideouts" for criminal groups that are "largely Colombian, and which your government allowed to infiltrate our country due to negligence regarding your border."

"President Petro, your statements are false," Noboa said. "We are operating within our own territory, not yours."

Colombia and Ecuador share a 586-kilometer (364-mile) border where Colombian guerrilla groups and criminal organizations from both countries operate. They engage in trafficking of drugs, weapons and people, and illegal mining.

The countries faced a similar rise in tensions in 2008 when Colombia's then-president Alvaro Uribe ordered a strike on Ecuadoran soil to take out a FARC commander.

Ecuador recently began anti-drug operations with US support and also joined the "Shield of the Americas," a 17-nation coalition set up by Trump this month to combat drug trafficking in the region.

Colombia, like other left-wing governments in Latin America, was not invited to join the group even as Bogota and Washington agreed recently to coordinate their efforts against Colombian cartels and guerrilla groups.

The exclusion drew a complaint from Petro.

About 70 percent of the cocaine produced in Colombia and Peru -- the world's largest producers of the drug -- transits through Ecuador to be exported via its Pacific ports.