Thirty-two more suspected terrorists arrived at this U.S. naval base Friday, but American officials would not say whether the suspects were detained during the war in Afghanistan.

The new arrivals boosted the prison population at this military outpost in eastern Cuba to 363, representing at least 34 nationalities. A group of 32 prisoners also arrived on Wednesday.

Officials refused to say where the C-140 military plane had flown from. Previously, they said planesida fighters.

A representative from the International Committee for the Red Cross, the only independent group allowed contact with the detainees, witnessed Friday's arrivals.

Guards led the men off the C-140 plane and held them by the collar as another guard searched mouths, hands, legs and shoes. All wore orange jumpsuits and yellow mittens.

The detainees were shackled and also wore whited-out goggles and ear muffs, security measures to prevent resistance. They also had on surgical masks to protect soldiers against tuberculosis.

A battalion of soldiers in riot gear and four Humvees armed with .50-caliber machine guns stood on alert nearby while a helicopter circled above.

The newest arrivals then were taken to Camp Delta, the permanent detention facility that replaced the hastily built Camp X-ray and its chain-link cells.

The men will be fingerprinted, photographed and examined during their processing. They also will shower, receive blankets and shampoo, and be allowed to write to their families.

Camp Delta has room for another 45 detainees but officials say a bulk of those cells likely will remain empty for security reasons.

Meanwhile, construction crews worked furiously to finish cells at the new prison. An extension with 204 cells is expected to be ready by May.

"This has probably been the most efficient operation in terms of time and processing," said Maj. James Bell, a spokesman for the detention mission. "The soldiers are just getting better at what they do."

Friday's new arrivals followed one detainee's departure from the base. The prisoner, who left either Wednesday or Thursday, was only the second to leave the base since the United States began using it three months ago to house detainees from the war on terrorism.

The first — 22-year-old Yasser Esam Hamdi — was flown to the United States on April 5 after records showed he was an American citizen born in Baton Rouge, La., to Saudi parents.

The Miami Herald on Friday quoted a Pentagon source as saying the other man was "repatriated back" to Afghanistan in an apparent admission he was not suspected of crimes against U.S. soldiers and not believed to have any important knowledge concerning terrorism.

The U.S. government is intensifying its interrogation process here, hoping to further its search for renegade Taliban and al-Qaida members and the elusive Osama bin Laden, believed to be the mastermind of the Sept. 11 terror attacks on the United States.

"From an interrogation seat, all the appropriate steps and measures are being taken to turn the interrogations up a notch," Maj. Riccoh Player, a Pentagon spokesman, said this week.

At Camp Delta, the men have less contact with each other than at Camp X-ray. Except for a window in each cell, the camp is cloaked by camouflage netting. Journalists no longer can see the inmates.

Officials believe the isolation may make them talk, Player said.