Costa Rica and Panama are coordinating to expedite southbound migrant transit through their countries along the same route that carried hundreds of thousands north in recent years, officials said Monday.

“Panama cannot end up becoming a black hole for deported migrants,” said Juan Pappier, deputy director of Human Rights Watch in the Americas. “Migrants have the right to communicate with their families, to seek lawyers and Panama must guarantee transparency about the situation in which they find themselves.”

Officials in Costa Rica and Panama are confiscating migrants' passports and cellphones, denying them access to legal services and moving them between remote outposts as they wrestle with the logistics of a suddenly reversed migration flow.