Colombian President Juan Manuel Santos, center, chairs a meeting with Foreign Minister Maria Angela Holguin (first left), Defense Minister Luis Carlos Villegas (first right) and leaders of the national police and army in Bogotá, Colombia's capital. (Presidential office via Agence France-Presse via Getty Images)

A group of about 60 Venezuelan soldiers crossed the border into Colombia this week, set up camp on a banana plantation and flew their national flag for a few days, an incident Colombian President Juan Manuel Santos called “a totally unacceptable” violation of national sovereignty.

Santos said Thursday he spoke personally to Venezuelan President Nicolás Maduro about the incursion, and following their conversation, Maduro ordered the troops to return to their country. By Thursday afternoon, the soldiers had decamped for Venezuela and offered to pay for any damage to the crops.

The puzzling episode has kept tensions simmering between the two countries, whose busy land border has become the site of spillover problems from crisis-wracked Venezuela.

Santos has generally refrained from criticizing Maduro as forcefully as other Latin American leaders, but Colombia joined the United States and a dozen other nations in the region Thursday in a statement calling on Venezuela to release political prisoners and hold new elections.

Within hours of that statement's release, Venezuela's foreign ministry broke its silence on the border dispute and lashed out at the Colombian government for presenting what it called a "distorted" version of events.

The Venezuelan troops were engaged in routine patrols, according to a communique read by foreign minister Delcy Rodriguez, who said the shifting course of the swollen Arauca River that divides the two countries meant the soldiers were not, in fact, on Colombian soil. The river is vulnerable to the effects of climate change, her statement added.

"In the face of these falsehoods aimed at producing confrontation between fraternal nations, we want to make a point of repudiating the constant insults and the economic, diplomatic, political, commercial and financial attacks on Venezuela by the Colombian oligarchy," Rodriguez declared. "We are the victims of never-ending conspiracies and provocations originating in Colombia, and all manner of cross-border crimes that threaten the peace, development and territorial integrity of our nation."

She joined the Colombian government in urging a diplomatic resolution to the border dispute.

During his statement earlier in the day, Santos said he had sent aides to inspect the Venezuelan troops’ camp, and its location was clearly on the Colombian side of the river.

“The Venezuelan troops are in Colombian territory,” he said, after convening an emergency cabinet meeting. “There is no doubt about it.”

The uniformed Venezuelan soldiers reportedly insisted to Colombian officials that the land was theirs, and they were joined this week by dozens of civilians who forded the river to join the camp, according to Colombia’s El Tiempo newspaper.

The farmer who owns the banana plantation was forced to leave, El Tiempo reported. The governor of the Colombian state where the troops set up their camp said local residents were further rankled by the sight of the Venezuelan flag flying on their side of the river.

The somewhat lawless and highly porous boundary between the two countries is riddled with informal crossings, and it’s not unusual for residents to casually move back and forth. Huge numbers of Venezuelans rely on Colombian markets along the border to obtain basic food items that have grown scarce back home, or to receive the medical care that Venezuela’s breakdown has left lacking.

But it’s rare for police or soldiers from the two nations to cross the border in territorial incursions such as the one this week. Santos said he had directed Colombian troops to remain in the area, and agreed in his talk with Maduro to maintain open channels for “dialogue” and diplomacy.

An unnamed Venezuelan military official quoted by the EFE news agency said his country’s forces moved into the area because they recognized a “geospatial” demarcation line between the two nations. He said that the river’s course had also been altered by dredging in a manner that favored Colombia.

The official said the area briefly occupied by the Venezuelan troops also sits above oil deposits with the potential to produce 50,000 barrels a day of light crude.