Scores of detainees have started a new hunger strike at the U.S. prison for terror suspects in Guantanamo Bay (search), Cuba, demanding to be put on trial or released, human rights lawyers said Wednesday.

Many have been held more than 3 1/2 years without charge or access to lawyers. Most were captured in the Afghanistan (search) war, suspected of ties to Al Qaeda (search) or the ousted Taliban (search) regime that sheltered the terrorist network.

The hunger-striking detainees allege the Pentagon reneged on promises to bring the detention camp into compliance with Geneva Conventions if they ended a hunger strike this summer involving up to 200 of the 500-plus detained men from some 40 countries, the New York-based Center for Constitutional Rights (search) said.

The military said only 52 prisoners were involved in the first strike. An attorney with the center, Gitanjali Gutierrez said the Pentagon "hid evidence of the hunger strike and prisoner abuse from visiting senators and the public."

"Prisoners are now prepared to die in an effort to receive a fair hearing and humane treatment," Gutierrez said.

Spokesmen for the detention mission at Guantanamo could not immediately be reached for comment. Several telephones in the public affairs office there rang without response. There was no immediate response to e-mail messages. A Pentagon spokesman referred a reporter to the military's Miami-based Southern Command, which said comment could come only directly from Guantanamo.

Detainee Binyam "Benjamin" Mohammed al-Habashi said the military promised that if they stopped the June-July hunger strike "they would bring the prison into compliance with the Geneva Conventions."

That strike ended July 28, but nothing had changed by Aug. 11, said Mohammed, an Ethiopian refugee detained in Pakistan in 2002.

Mohammed said some 150 detainees began refusing meals at the beginning of August and were joined by another 60 on Aug. 11. He told his lawyer he had planned to start his fast Aug. 12,

"I do not plan to stop until I either die or we are respected. People will definitely die," he said.