About 1,000 Cubans and Africans invaded Costa Rica Wednesday, and a Costa Rican official blamed the United States.
The invaders are some of those migrants who have been stranded on the Panamá side of the border for months.
Costa Rica sent police and immigration agents to the border in an effort to contain the invasion. The unhappy migrants blocked a street and ignited a clash with police.
Witnesses confirmed acts of violence and damaged vehicles in the areas surrounding Paso Canoas at the border.
The official, Alejandro Solano, a vice chancellor at the foreign ministry, said that U.S. law encourages the migration of Cubans.
He was talking about the Cuban Adjustment Act, Cold War legislation that gives Cubans who reach the United States by land the right to residency there.
Solano claims that such a law encourages human trafficking and organized crime. He said that the government will send a protest letter to U.S. President Barack Obama.
The Costa Rica government said it will not allow violence in its territory. A statement said the country does not have the resources to care for more migrants. Still, the central government sent workers from the Instituto Mixto de Ayuda Social, the Instituto Nacional de las Mujeres and the Patronato Nacional de la Infancia child welfare agency to the border.
Costa Rican officials housed about 9,000 Cuban migrants starting in November when Nicaragua closed its border to them. Eventually the government worked out a transportation plan to airlift the migrants north so they could continue on foot to the United States.
Most of the invaders seemed to be men. The Costa Rican government said that it would return the illegal immigrants to Panamá. However, some officials noted that those detained on Costa Rican soil would have the right to a hearing.