Nicaragua has sent more than 1,000 Cuban migrants, heading to the United States, back to Costa Rica, accusing San Jose of deliberately sparking a humanitarian crisis.
The diplomatic crisis began last week when Costa Rica said it would issue temporary transit visas to more than 1,000 Cubans it detained in recent days after crossing into the country from Panama.
Costa Rica's immigration chief said the government initially was deporting Cubans who arrived without proper visas, but criminal gangs began using the deportation process to facilitate the illegal transportation of migrants to the United States.
Costa Rica's Foreign Ministry chided Nicaragua for using security forces to detain the migrants, citing unconfirmed reports that soldiers used tear gas.
Nicaragua said there were some altercations when migrants stormed the Penas Blancas border post on Sunday.
In recent months there has been a surge in Cubans seeking to reach the United States, by way of Mexico and Central America, following a thawing of relations between the former Cold War foes. The migrants now fear long standing asylum rights for Cuban immigrants in the United States will end.
Some material for this report came from AP, AFP and Reuters.