Their loved ones were picked up by U.S. immigration authorities, deported to El Salvador and then jailed in a notorious maximum-security prison. Now, more than a dozen families are suing the Salvadoran government, accusing it of illegally keeping their sons, brothers, nephews and partners behind bars for nearly two months.

The lawsuit, filed on Fridaybefore the Inter-American Commission of Human Rights by a coalition of migrant rights lawyers representing the families, names 18 Venezuelan nationals who are being held at the Terrorism Confinement Center, known as CECOT — a strict and austere megaprison at the center of a deportation deal between El Salvador and the Trump administration.

Since March, none of the families have had news of their imprisoned relatives, most of whom had pending or approved applications for asylum or other kinds of humanitarian protection in the United States, according to a copy of the suit seen by The New York Times.

“They’ve all been deported without due process, excluded from any protection of the law and are in a situation of enforced disappearance,” said Isabel C. Roby, a senior staff attorney at Robert F. Kennedy Human Rights, one of the groups bringing the lawsuit.

Spokespeople for El Salvador’s government did not immediately respond to a request for comment.

The White House has found an important ally in El Salvador’s president, Nayib Bukele, to carry out its deportation policy. At least 288 U.S. deportees — mostly Venezuelans and several dozen Salvadorans, including a man deported from Maryland in error — are in CECOT custody, the recent lawsuit estimates, but the exact number is not known because neither government has revealed their identities.

The complaint requests that the commission order the Bukele government to immediately release the 18 migrants held incommunicado at the prison and facilitate their return either to the United States or to another country where they would be safe.