Colombia's government Monday denounced an incursion by an Ecuadoran military helicopter into its airspace on the weekend, which Quito called an "involuntary flyover" it regretted.
The incident happened on Sunday at 11:10 am (1610 GMT), when a Gazelle attack helicopter belonging to the Ecuadoran air force was intercepted by two Colombian Black Hawk choppers over Colombian territory, the Colombian presidency said in a statement.
The Colombian aircraft "tried to establish radio contact with said helicopter with negative results. International procedures established for such cases then followed," it said.
The Gazelle was ordered to land at an airport in the Colombian town of Tumaco and put under escort by the Black Hawks, but it "descended suddenly and flew low to the south, not completing the instructions given."
Military chiefs called off the interception, the statement said, adding that Ecuador's government was informed.
Ecuador later admitted to an accidental incursion by one of its helicopters into Colombia, but denied the pilots disobeyed an "invitation" by Colombian officials to land.
A foreign ministry statement in Quito said the helicopter was not armed and was on a supply mission to a military base near the border.
"Due to a navigation error (the helicopter) flew into Colombian airspace for a few minutes without authorization," it added.
"The Ecuadoran government regrets the involuntary overflight, stressing it was a totally accidental event."
The incident played out against tensions left over from a Colombian air and ground military incursion into Ecuador on March 1 in which a Colombian rebel leader was killed.
Ecuador broke off diplomatic relations with Colombia following that attack, and, with ally Venezuela, ordered troops to its Colombian border.
The dispute subsided at a summit in the Dominican Republic a week later when the leaders of the three countries shook hands.
But Quito has maintained a chill towards Bogota which intensified with the revelation last week that an Ecuadoran man was also killed in the Colombian raid, in unclear circumstances.