U.S. Homeland Security Secretary Kristi Noem on Wednesday is expected to visit a mega-prison in El Salvador holding Venezuelans deported by the U.S. as civil rights groups challenge the removals in a high-profile court battle.

Homeland Security Secretary Kristi Noem on Wednesday visited the Salvadoran mega-prison where the U.S. has sent hundreds of Venezuelans, accusing them of ties to gangs. Noem’s three-day trip around the Americas began at El Salvador’s Terrorism Confinement Center, more commonly known as CECOT.

US Homeland Security Secretary Kristi Noem on Wednesday visited the high-security El Salvador prison where Venezuelans who the Trump administration alleges are gang members have been held since their removal from the United States.