The United States has cleared out the last migrants being held at its naval base at Guantanamo Bay, Cuba, sending them back to the U.S. mainland as they await deportation.

Two U.S. defense officials told VOA on Wednesday that 40 detainees, including 23 “high-threat illegal aliens” incarcerated at the base’s detention center, were flown to Louisiana on Tuesday.

The officials, speaking on the condition of anonymity to discuss the operation, said the detainees were flown aboard a nonmilitary aircraft at the direction of officials with Immigration and Customs Enforcement.

Neither ICE nor its parent agency, the Department of Homeland Security, have responded to requests for comment.

Last week, in response to a request for updates on the detainees being held at Guantanamo, an ICE spokesperson declined comment “due to pending litigation.”

ICE and DHS, which has been spearheading the U.S. deportation efforts under President Donald Trump, have repeatedly declined to respond to questions about the identities of the detainees, their countries of origin or the crimes with which they are charged.

U.S. Homeland Security Secretary Kristi Noem said on social media that many of the “high-threat illegal aliens” sent to Guantanamo are members of the Venezuelan street gang Tren de Aragua and have confessed to or been charged with murder, attempted murder, assault, weapons trafficking and drug crimes.

The Trump administration announced plans to use the U.S. naval base at Guantanamo Bay to hold migrants slated for deportation in late January.

At the time, Noem told reporters that the facilities would be used to house “the worst of the worst.”

Defense Secretary Pete Hegseth, also speaking in late January, called the detention center at Guantanamo Bay “the prefect place” to hold criminals slated for removal, but also said the base’s migrant operations center, first built in the 1990s, would also be opened for nonviolent migrants awaiting deportation.

The first detainees began arriving at Guantanamo Bay in February aboard U.S. military cargo jets, some staying for days or weeks before being deported.

At times, the base held nearly 200 detainees between its prison and migrant facilities.

Last month, ICE at one point deported 177 detainees from Guantanamo Bay to Honduras, from which they were to be taken to Venezuela for repatriation, before bringing in more detainees.

Immigration rights groups, including the American Civil Liberties Union, have filed multiple lawsuits against the U.S. government over its use of Guantanamo Bay.

One suit, filed earlier this month, seeks to stop U.S. officials from transferring migrants to the base, alleging the moves violate U.S. law.

An earlier lawsuit filed in February alleged the U.S. government had prevented family members and lawyers from contacting the detainees.

DHS has dismissed the allegations in the lawsuits.

“The American Civil Liberties Union appears far more interested in promoting open borders and disrupting public safety missions than in protecting the civil liberties of Americans — they should consider changing their name,” a DHS spokesperson told VOA in a statement earlier this month. “In the meantime, we will continue working with DOJ (Department of Justice) to fend off these baseless legal challenges.”