WASHINGTON — Pressure mounted on the U.S. Defense Department Friday after multiple U.S. senators called for investigations into reports that U.S. military interrogators worked with forces from the United Arab Emirates who are accused of torturing detainees in Yemen.

John McCain, Republican chairman of the Senate Armed Services Committee, and the ranking Democrat, Jack Reed, called the reports “deeply disturbing.”

The reports were revealed in an investigation by The Associated Press published Thursday.

That same day, McCain and Reed wrote a letter to Defense Secretary Jim Mattis asking him to conduct an immediate review of the reported abuse and what U.S. forces knew.

“Even the suggestion that the United States tolerates torture by our foreign partners compromises our national security mission by undermining the moral principle that distinguishes us from our enemies – our belief that all people possess basic human rights,” the senators wrote Mattis. “We are confident that you find these allegations as extremely troubling as we do.”