San Jose, Shawwal 08, 1437, July 13, 2016, SPA -- A new migration crisis is brewing in Costa Rica as thousands of US-bound migrants, mostly from Africa, remain stranded at the country's border with Nicaragua, a local police chief said Wednesday, according to dpa. More than 3,000 migrants, mostly from African countries including Congo, have arrived in Costa Rica since April, Katia Chavarria, police chief of the Penas Blancas border region, told local media. Most traveled by ship from Africa to Brazil, and then by land up through South and Central America on their way to the United States. But Nicaragua closed its border to migrants in November, leaving them stranded en route. Chavarria said migrants are living in precarious conditions, in tent camps without drinking water or sanitary facilities. On Tuesday, a group of African migrants blocked a highway at the Penas Blancas border station, demanding Nicaragua let them cross. Immigration authorities estimate as many as 20,000 more migrants could attempt to reach the US through Central America in the coming months. Earlier this year, 8,000 Cuban migrants were airlifted to El Salvador for the onward journey to the US. US immigration rules allow Cuban migrants a fast track to legal residency not available to other groups. --SPA 22:11 LOCAL TIME 19:11 GMT www.spa.gov.sa/w