By Ted Hesson WASHINGTON (Reuters) -A U.S. civil rights group on Saturday sued to block the Trump administration from potentially transferring 10 migrants from the U.S. to a naval base in Guantanamo Bay,

The lawsuit says there is no legitimate reason to send migrants to Guantánamo because the U.S. has ample detention facility.

The base had been cleared of migrants since Thursday, after the government sent 177 to Venezuela and one back to the United States.

It’s their second legal challenge in less than a month over plans for holding up to 30,000 immigrants there for deportation.

The administration flew almost all of the migrants it had held in the facility in Cuba to Honduras, and one to detention in the U.S., NBC News has learned.

The new case, which for now is asking for a court to block the transfer of 10 men to the offshore base, is the first to directly challenge the policy.

Attorneys filed a lawsuit against the Trump administration Saturday to halt the transfer of 10 migrants detained in the U.S. to Guantánamo Bay Naval Base in Cuba. This marks their second legal challenge in under a month against plans to use the facility for large-scale immigrant detention before deportation.

Immigrant rights groups sued the Trump administration on Saturday in hopes of stopping the transfer of migrants from the U.S. to Guantanamo Bay.

Civil rights attorneys sued the Trump administration Saturday to prevent it from transferring 10 migrants detained in the U.S. to Guantanamo Bay, Cuba, and filed statements from men held there who said they were mistreated there in conditions that of one of them called ''a living hell.