Puerto Rico ? More Guantanamo Bay detainees have joined a hunger strike, raising the total to 89, and six of them were being force-fed, the U.S. military said Thursday.

The strike – which last weekend jumped from three participants to 75 – is now the biggest of the year at the U.S. prison in Cuba, where about 460 men are being held on suspicion of links to al-Qaida or the Taliban.

The U.S. military said the detainees were trying to pressure the United States to release them, but a human rights attorney described the strike as a desperate appeal for justice.

Six hunger strikers were being force-fed, said Navy Cmdr. Robert Durand – two more than last weekend.

“All are being closely monitored by the … medical staff and being counseled on the health effects of long-term hunger striking,” Durand said in a statement from Guantanamo Bay.