Human rights organizations are asking Secretary of Defense Chuck Hagel to order troops to abandon the practice of force-feeding prisoners at Guantanamo, a move that could permit them starve to death if they choose.

The American Civil Liberties Union, Center for Victims of Torture, Human Rights Watch and 17 other groups wrote the Pentagon on Monday, hours after the Qatar-based Al-Jazeera website posted the prison’s 30-page forced-feeding procedures with the headline “military document lays bare the brutality of force-feeding.”

The letter called Guantanamo’s force-feeding process “inherently cruel, inhuman, and degrading.”

“We urgently request that you order the immediate and permanent cessation of all force-feeding of Guantanamo prisoners who are competent and capable of forming a rational judgment as to the consequences of refusing food,” they wrote.

The letter also asked Hagel to allow “independent medical professionals” access to the prison to “review and monitor the status of hunger-striking prisoners in a manner consistent with international ethical standards.”

A surgeon, Navy Capt. Daryl K. Daniels, took charge of the medical team on Friday, according to an announcement in the base newsletter. It said he received his medical degree from Yale in 1991 and joined the Navy after doing a residency in general surgery at the University of New Mexico in 1996.

As of Tuesday, the U.S. military counted 100 of the 166 captives there as hunger strikers. It said 29 prisoners were being force-fed, five of them at the detention center hospital.

Guantanamo earlier called in reinforcements and now has about 140 Navy doctors, nurses and medics called corpsmen working at the prison complex, enough to handle the current caseload, said Army Col. Greg Julian, a spokesman for the Southern Command, which supervises the prison.

The Defense Department had no comment Tuesday on whether Hagel had read the letter.

“The Department will reply directly to the letter in the form of direct correspondence,” said Marine Maj. Jeff Pool, a Pentagon spokesman. “The Department does not respond to correspondence via the press.”

On Monday, the Al-Jazeera news channel put a spotlight on the forced-feeding practices by posting the portion of the military’s so-called Standard Operating Procedures, or SOPs, that instruct on how to strap a captive into a restraint chair and pump cans of nutritional supplement into his stomach via a tube snaked up his nose.

The document provides elaborate instructions to the Army guards and Navy medical staff, including a recommendation that the captive not be restrained to the chair for more than two hours to achieve a “feeding” that “can be completed comfortably over 20 to 30 minutes.”

It gives a nurse authority to order a soldier to wash the hands of a detainee brought in shackles to the restraint chair with feces on his hands.

And it reflects two “talking points” that military medical staff have repeatedly told members of the media visiting the prison medical facilities:

— A captive can request olive oil rather than a “sterile surgical lubricant” or “viscous lidocaine” to lubricate his nostril before the Navy medic snakes the feeding tube up his nose.

— A long-term hunger striker who cooperates and comes to a guard on command is rewarded with “single-point leg restraint” rather than the full body shackle into the restraint chair. The procedures specify the language of the command, “It is time to feed.”