The U.S military on Friday released 454 detainees from the Abu Ghraib prison, the center of the abuse scandal, taking them out by bus at around 8 a.m. bound for Baghdad and other cities.

Brig. Gen. Mark Kimmitt, the senior military spokesman in Iraq, said an additional 394 prisoners would be freed May 28.

Early this month, shortly after the abuse of prisoners by U.S. soldiers became public, the U.S. general overseeing the prison system in Iraq said the population of the prison would be cut by more than half. The Friday release was announced earlier this week.

The prison has held up to 7,000 inmates at a time, according to a report by Army Maj. Antonio M. Taguba. The release of the prisoners came two days after Spec. Jeremy C. Sivits was sentenced to a year in prison for his role in abusing prisoners at Abu Ghraib. He was the first of seven charged members of the 372nd Military Police Company to be convicted for taking part in the abuse.

During Friday prayers at the Umm al Qurra mosque in Baghdad, Ahmed Abdul Ghafour Samarrae, a Sunni cleric, said the Islamic Party had called for a sit-in on Monday at the prison to protest the mistreatment of Iraqi detainees.

"All of the families of the prisoners and the people should come, and we will sit in until they release our prisoners," he said. "For how long they are going to keep them behind bars? They must organize themselves and go there."

Hamza Abdulla, 29, a former officer in the Republican Guard who attended the prayer service, said there was no reason for the guards to mistreat the detainees.

"They are only guards," he said. "They are not investigators, and they are not questioning those prisoners. They are doing this for fun, and they should be punished. Whoever should punish them should put in his consideration the tradition of Iraq, because Americans will forget about these abuses after the U.S. elections. But those Iraqis will keep remembering for a long time."

[On Saturday, an explosion shook an area of eastern Baghdad near the former headquarters of the Iraqi civil security force, according to news services. Witnesses told the Reuters news agency that at least five people were killed.]

Speaking at a briefing Friday in Baghdad, Kimmitt said all U.S. military detention facilities in Iraq adhere to the Geneva Conventions governing the treatment of prisoners of war. He said that torture is not tolerated and not permitted under Army regulations and that any suggestion to the contrary is "false and offensive."

After leaving Abu Ghraib, Abdul Salam Hussain Jassim, 18, was quoted by the Associated Press as saying he had been held for three months. He said he and others were rounded up after an explosion on a street in Baqubah, 30 miles northeast of Baghdad. "Don't even talk about torture," he said. "They destroyed me."

Jassim said a family of five brothers and sisters was detained in the same block with him and that one of the men was beaten so badly that he died two days later, the news service reported.

Meanwhile, the U.S.-led occupation authority announced that it had two suspects in custody in connection with the kidnapping and beheading of U.S. citizen Nicholas Berg.

Kimmitt said coalition forces had detained four suspects but let two of them go after questioning. "We may find out" that the two who remain in custody "have no association with the murder, but we will continue to question them," he said.

In Rome, the Italian Red Cross announced that its officials in Iraq had been given a body believed to be that of Fabrizio Quattrocchi, an Italian killed by his abductors in Iraq last month, the Reuters news service reported.

Quattrocchi was kidnapped on April 12 along with Salvatore Stefio, Umberto Cupertino and Maurizio Agliana outside Baghdad, where they were working for a private U.S. security firm. He was shot dead after the captors demanded Italy withdraw its 2,700 troops from Iraq. The other three Italians are still in the hands of the kidnappers.

In other developments, the last troops from a 1,400-member Spanish military contingent crossed from Iraq into Kuwait, officials in Madrid announced. The country's new Socialist government had already removed its field operation troops. The soldiers who left Friday were logistical specialists who stayed behind to pack up equipment for shipment home.

Fran Sevilla, a Spanish radio reporter, was freed Friday after being held captive for four hours, his station said, according to the Associated Press. He was intercepted after traveling from Diwaniyah to Najaf to report on a sermon by the anti-U.S. Shiite cleric Moqtada Sadr, Spanish National Radio said.

Special correspondent Naseer Nouri contributed to this report.