Eleven prisoners held at the Guantanamo Bay detention filed a legal challenge Thursday against President Donald Trump, whose administration has not released or transferred anyone from the U.S. base in Cuba over the past year.

Lawyers for the men argue in a challenge filed in U.S. District Court in Washington that the apparent policy of no releases amounts to arbitrary “perpetual detention” that violates the Constitution and acts of Congress establishing the rights of the men held at Guantanamo.

Their complaint, filed on the 16th anniversary of the opening of the detention center on the base in southeast Cuba, is unusual legal step since this type of action, known as habeas corpus petition, is typically filed on behalf of individuals rather than a group of prisoners.

The filing notes that President George W. Bush and President Barack Obama together released nearly 750 men by making case by case determinations on individual detainees.

“Continuing, still indefinite detention after all this time is unprecedented and experimental,” said Pardiss Kebriaei, an attorney from the Center for Constitutional Rights who represents prisoner Sharqawi Al Hajj of Yemen.

Trump has not formally released a Guantanamo policy but his administration has not released any of the five prisoners who were determined to be eligible to depart by multiple government agencies and not added any additional men to the cleared list. There are 41 men still held at Guantanamo.

A Pentagon spokeswoman for Guantanamo issues, Navy Cmdr. Sarah Higgins, said that the administration is still considering whether to transfer detainees. The Department of Justice is reviewing the complaint and had no further comment, spokeswoman Lauren Ehrsam said.

Trump said of Guantanamo during the campaign that he planned to “load it up with some bad dudes.” Shortly before he took office in January 2017, he said on Twitter that there should be no further releases, adding that the prisoners are “extremely dangerous people and should be not allowed back onto the battlefield.”

The prisoners’ legal challenge argues that the Authorized Use of Military Force adopted by Congress in 2001 only allows “limited military detention” and not “perpetual detention disconnected from any legitimate purpose.” They also note that because of age and ill health, some may not survive to the end of the Trump administration.

(AP)