LONDON (AP) – An international group of doctors on Friday called on the U.S. military to stop force feeding detainees at Guantanamo Bay, Cuba, who are on hunger strikes. In a rare letter to the medical journal, The Lancet, 263 doctors appealed to the American Medical Association, which endorses a World Medical Association ban on the force feeding of patients, to pressure military physicians to stop the practice.

There were five detainees on hunger strike last month. Three were being forcibly fed.

“Doctors force-feeding prisoners at Guantanamo are acting as an arm of the military and have abrogated their medical-ethical duties,” said Dr. William Hopkins, a psychiatrist at Barnet Hospital in southern England, and a signatory of the letter.

The World Medical Association says that a prisoner should not be forcibly fed if a physician determines that the patient is capable of making a decision to refuse treatment.

There was no immediate response by the U.S. Department of Defense.