American AC-130 gunships and tanks battered militia positions early Friday near two shrines in the holy city of Karbala, killing 18 fighters loyal to a rebel cleric, the US military said, while 450 Iraqis were released from the Abu Ghraib jail at the center of the prisoner abuse scandal.

Four people were detained in the killing of American Nicholas Berg, whose decapitation was captured on videotape, but two had been released, Brig. Gen. Mark Kimmitt said Friday. An Iraqi security official said the group that killed the 26-year-old Pennsylvania man was led by a relative of Saddam Hussein.

The suspects were former members of Saddam Hussein's Fedayeen paramilitary organization, the Iraqi security official said on condition of anonymity. Iraqi police arrested them on May 14 in a house in Salaheddin province, north of Baghdad. The province includes Tikrit, Saddam's hometown.

Separately, Associated Press Television News footage of a US attack that survivors said hit a wedding party, killing up to 45 people on Thursday, arrived in Baghdad.

It showed pieces of rockets, bullet shellings, pots and pans, destroyed musical instruments, pillows, mattresses and blankets scattered at the devastated site. Tufts of women's hair and bits of what appear to be human flesh lie in a shallow ditch. An arm lay in the rubble. A crowd of young men stand around a huge blood stain on the ground.

The United States has insisted the target was a safehouse for infiltrators slipping across the border to fight coalition soldiers in Iraq. In Baghdad, Kimmitt repeated that claim Thursday, but said the US military would investigate after Iraqi officials reported the survivors' story.

US forces withdrew from the Mukhayam mosque in the center of Karbala, the scene of fierce fighting last week during which coalition forces ousted insurgents who were using it as a base of operations. But they said patrols in the city would continue. Two Iranian pilgrims and a driver for Al-Jazeera also were killed in the fighting, according to hospital officials and the pan-Arab TV network.

Fighting between American forces and anti-US cleric Muqtada al-Sadr's militia also was heavy in Najaf and neighboring Kufa, south of Baghdad. Explosions rocked the center of Najaf, near local government buildings, and Friday prayers were canceled because of the violence. A huge fire raged in a vegetable market.

A convoy of at least six buses, accompanied by U. troops in armored vehicles and jeeps, took the detainees from the Abu Ghraib prison on the western outskirts of Baghdad to Tikrit and Baqouba, north of the capital.

The release came as new photographs and shots from a video of alleged abuse and sexual humiliation of Iraqi prisoners were published in The Washington Post's Friday editions. The newspaper reported that some prisoners at Abu Ghraib were ridden like animals, fondled by female soldiers, forced to curse their religion and required to retrieve their food from toilets.

The newspaper said the material, including secret sworn statements from prisoners, came from evidence being assembled from investigations into possible criminal charges against US soldiers.

The first American accused in the scandal, Spc. Jeremy C. Sivits, was sentenced on Wednesday to a year in prison for sexually humiliating detainees and taking a photo of prisoners stacked naked in a human pyramid.

Some of those who were freed told stories of beatings and psychological abuse. Freed detainees kissed the ground and kneeled to pray after walking out of the police compound in Baqouba, 50 miles northeast of Baghdad.

Abdul Salam Hussain Jassim, 18, said he was held for three months after an explosion.

"Don't even talk about torture. They destroyed me," Jassim said of his detention. He said a family of five brothers and sisters was detained in the same block and that one of the men was beaten so badly he died two days later.

The US military said 450 prisoners were released.

The military periodically frees prisoners from Abu Ghraib, which was also notorious as the site of executions and torture during Saddam Hussein's regime. Between 3,000 and 4,000 people are still believed held at Abu Ghraib.

The military is still sending detainees who are considered security risks to Abu Ghraib.

The fighting in Karbala started after insurgents fired several rocket-propelled grenades at US tanks that were patrolling on the outskirts of the so-called "Old City," a maze of alleyways and cluttered buildings, said US Army Col. Pete Mansoor of the 1st Armored Division.

The tanks returned fire, and more than two hours of heavy fighting followed. Smoke billowed from burning buildings. Explosions lit up the night sky and reverberated throughout the city. Electric lights flickered on and off. By 3 am, the fighting had stopped.

Much of the fighting was near the city's Imam Hussein and Imam Abbas shrines, which US forces allege are being used by militiamen as firing positions or protective cover. Mansoor said the shrines were not damaged.

The military says it is doing its best to avoid damage to the gold-domed shrines, which could infuriate Shiite Muslims who are not involved in the conflict. Al-Sadr, who launched an uprising against the US-led occupation of Iraq last month, has accused US forces of desecrating holy sites.

"Don't let my killing or arrest be an excuse to end what you're doing, supporting the truth and standing up to the wrong," al-Sadr said in a sermon to 15,000 worshippers at Friday prayers in the city of Kufa. Two people died in fighting in Kufa, witnesses said.

Mansoor said 18 insurgents died in Karbala. Dr. Abbas Falih al-Hassani of Karbala's al-Hussein hospital said 12 people died, including two Iranian pilgrims. Thirteen were injured.

The dead included an Iraqi driver for a camera crew of the Al-Jazeera television network, the station reported.

Rashid Hamid Wali, 38, who was shot in the head while assisting colleagues filming the clashes, is the second Al-Jazeera crew member to be killed in Iraq since the US-led force invaded the country last year. The station called on the U.S. military to investigate.

The network broadcast scenes of Wali's funeral in Iraq, interviewing members of his family and colleagues -- who blamed the US Army for his killing.

The US military says al-Sadr, who is wanted in the murder of a rival moderate cleric last year, must disband his militia. Al-Sadr has refused.

One civilian died and another was injured in Najaf when their car was caught in fighting, hospital officials said. At least 14 people were injured.

In the northern city of Kirkuk, American troops detained a representative of al-Sadr, Sheik Anwar al-Jinani and 10 supporters at a mosque, Iraqi authorities said. The press office of the US-led coalition in Baghdad said it had no information.

Near Baqouba, north of Baghdad, gunmen in pickup trucks opened fire Friday on a base of the Iraqi security forces, killing four, Iraqi authorities said. The slain men were members of the US -backed Iraqi Civil Defense Corps.

Insurgents often target Iraqis who are perceived as collaborators with the coalition.

Spain, meanwhile, completed its troop withdrawal from Iraq Friday as the last of its soldiers crossed the border into Kuwait, the Defense Ministry said.

The troops were the last of a contingent of logistics experts and other soldiers who had been packing up gear used by 1,300 soldiers sent by the previous government to take part in the US -led occupation.

(China Daily via agencies, May 22, 2004)