The repeated removal and insertion of the tubes has caused striking prisoners to vomit blood and experience intense pain they have equated with torture, the lawyers reported to a U.S. federal judge after visiting their clients at the base in eastern Cuba.

Prisoners said they were taunted by troops who said the treatment was intended to persuade them to end the hunger strike that began Aug. 9, the lawyers wrote in affidavits filed as part of a lawsuit in federal court in Washington seeking greater access to prisoners at the high-security jail for terror suspects.

Lt.-Col. Jeremy Martin, a military spokesman for the Guantanamo detention centre, said all detainees in the hunger strike are closely monitored by medical personnel and mistreatment is not tolerated, though he did not know the specific procedures for handling the feeding tubes.

"Detainees...are treated humanely," Martin said.

"Claims to the contrary are wholly inaccurate and blatantly misrepresent the excellent work being done here by honourable military and civilian professionals."

Guantanamo officials have said this latest hunger strike began with 76 detainees protesting against their confinement. Defence lawyers have cited other reasons as well, including complaints about food and water, alleged abuse by guards and interrogators and their desire to either face trial or be released.

Yousef al Shehri, 21, of Saudi Arabia, told his lawyers guards removed a nasal feeding tube from one prisoner and reinserted it into another without cleaning it first.

"These large tubes...were viewed by the detainees as objects of torture," lawyer Julia Tarver, whose firm represents 10 Saudi detainees, said in an affidavit.

"They were forcibly shoved up the detainees' noses and down into their stomachs."

At Guantanamo Bay, the U.S. military holds about 500 detainees suspected of terrorist activities. Martin said 25 detainees are on hunger strike, including 22 who are being force-fed.

The number participating in the strike reached a high of 131 in mid-September when detainees refused meals to commemorate the Sept. 11, 2001, terror attacks in the United States, Martin said.

Most detainees participating in the hunger strike are not confined to hospital beds and are permitted to exercise, take showers, send and receive mail, visit the detainee library and practise their religion, he said.

Defence lawyers who have visited the prison in recent weeks said their clients have lost substantial weight, appeared listless and depressed - and have insisted they will maintain the protest until conditions improve or they are released. A judge has not yet ruled on their request for increased access to the detainees and their medical records.

Notes of meetings between lawyers and their clients at the detention centr eare classified until they have been reviewed by the military and cleared for release.

Joshua Colangelo-Ryan, a lawyer for six men from Bahrain, said one of his clients, Isa al Murbati, has lost about 50 pounds as a result of the hunger strike.

"There's nothing in my mind that he intends to stop the hunger strike," said Colangelo-Ryan, who returned from Guantanamo on Monday.

Tarver, who returned from the base Oct. 2, said two of her clients were being force-fed and unable to walk.

"It's quite a drastic situation," she said.