(CNN) -- Costa Rica on Wednesday made its case in front of the permanent council of the Organization of American States that Nicaraguan troops had made an incursion onto their territory.
The neighboring Central American countries are in a border dispute over a parcel of land on the Atlantic coast, along the San Jose River, known as Calero Island.
Costa Rica claims that Nicaraguan troops are camped out on the Costa Rican side of the border, and that a Nicaraguan dredging project in the river is dumping sediment on its side as well.
The Costa Ricans also claim that a Costa Rican flag that was in the disputed area was taken down and replaced by a Nicaraguan flag.
"For the Costa Rican government, these actions constitute an unacceptable violation of its territorial integrity and sovereignty, and are absolutely indefensible by Nicaragua," Costa Rican Foreign Minister Rene Castro wrote in a letter to his Nicaraguan counterpart.
Costa Rica called for the emergency meeting of the OAS in an attempt to resolve the spat. The body called a recess to discuss the matter further, and had not reconvened by Wednesday night.
During his presentation Castro showed slides with maps of the disputed area, arguing that Nicaragua's own maps show that the area in question is in Costa Rican territory.
He also showed photos showing the area were sediment was allegedly being deposited, and where the Costa Rican flag had been taken down.
Nicaragua said that an earlier judgment by the United Nations upheld its rights over the river area, although it gave Costa Rica freedom to navigate it. Nicaragua said that all of its activities are within its borders.
"We categorically reject the allegations made by Costa Rica," the country's ambassador to the OAS, Denis Moncada, said. "Nicaragua has not violated the sovereignty of Costa Rica. Nor is the dredging, in Nicaraguan territory, affecting Costa Rican land. With these statements, Costa Rica has broken the diplomatic equilibrium that traditionally exists between the two nations."