Colombia has asked for an explanation from Venezuela after detecting two military airplanes that flew into its airspace late on Saturday, the defence ministry said. The two aircraft entered Colombia's northern La Guajira province, flew about 2.9 kilometers (1.8 miles) over the border and then circled above a military unit, Colombia's government said in a statement on Sunday.
The incident comes amid a diplomatic row between the conservative administration of Juan Manuel Santos in Colombia and the socialist government of Venezuela's President Nicolas Maduro.
Maduro closed several major border crossings and deported 1,300 Colombians last month in what he called a crackdown on smuggling and crime on the frontier. As many as 16,000 Colombians have left neighbouring Venezuela, according to the United Nations.
Maduro says he is protecting his country from criminals who smuggle everything from gasoline to flour across the border, but his political opponents say he is using Colombians as scapegoats to distract from Venezuela's economic crisis.
Colombians were made to leave their homes in several Venezuelan border towns and forced in many cases to cross rivers and bridges with their belongings on their backs.
Foreign Ministers from the two nations met on Saturday in Ecuador to try and smooth the way for the two leaders to meet and resolve the spat.