TIKRIT, Iraq (AP) _ American forces captured seven men _ two of them Saddam Hussein loyalists and five believed responsible for attacks on American troops _ during raids in the deposed leader's hometown, the military reported Monday.

Also, U.S. troops reported finding a huge arms cache near Humarrabi, 60 miles south of Baghdad, the military said.

The cache contained 300 artillery fuses and 70 bags of gunpowder stashed in five shipping containers, along with 400 cases of anti-aircraft ammunition and 200 rocket-propelled grenade rounds, 4th Infantry Division spokeswoman Maj. Josslyn Aberle said.

At the bombed U.N. headquarters in Baghdad, searchers were seen pulling five more bodies from the rubble. It was not immediately clear if the bodies were among the U.N. count of 20 dead.

An independent check by The Associated Press at nearby hospitals after the Tuesday bombing put the number of dead at 23. The top U.N. envoy in Iraq, Sergio Vieira de Mello, was among those killed in the suicide truck bomb attack.

A coffin draped with a United Nations flag was placed on top of a car and driven out of the compound, where searchers are still looking through debris for body parts and clues.

No U.S. troops were hurt in the raids that resulted in the capture of seven men in Tikrit, 120 miles north of Baghdad, according to the 4th Infantry Division 1st Battalion 22nd Regiment, which conducted the searches.

The military said the captured men and some still being sought were suspected of organizing regional cells of the Fedayeen Saddam, the militia loyal to Saddam and believed spearheading the guerrilla war against U.S. occupation forces. The military gave no identities.

Early Monday, two Iraqis were wounded when their vehicle attempted to avoid a U.S. checkpoint near Kirkuk, Aberle said. The soldiers manning the checkpoint opened fire and disabled the vehicle, she said. The Iraqis were being treated and were detained. Their wounds were not serious, she said.

An American soldier told an AP reporter Monday that the Republican Bridge over the Tigris River in central Baghdad had been closed for an hour Sunday night after U.S. forces discovered a bomb. He refused to give any other details.

In Najaf on Monday, mourners buried three guards who were killed in a bomb attack Sunday on the house of Mohammed Saeed al-Hakim, one of Iraq's most important Muslim Shiite clerics.

The bomb, a gas cylinder wired to explode, was placed along the outside wall of the house. It blew up just after noon prayers. A number of al-Hakim's family members were wounded. He suffered cuts on his neck.

``Obviously terrorist groups who belong to the former regime are behind this incident,'' said Abdel-Aziz Hakim, a relative of the religious leader.

Abdel-Aziz Hakim also is a member of the U.S.-picked Governing Council and leader of what was the armed wing of the Supreme Council for Islamic Revolution in Iraq, or SCIRI, headquartered in Iran before the war.

Iraqi newspapers had reported last week that Mohammed Saeed al-Hakim, who was under house arrest during the last days of Saddam's rule, had received threats against his life.

He was among a group of three top Shiite leaders who were threatened with death by a rival Shiite cleric shortly after Saddam was toppled April 9.

Mohammed Saeed Al-Hakim, in his late 60s, holds the highest theological title in Shiite Islam _ Ayatollah al-Uzma, which means Grand or Supreme Ayatollah.

Before the beginning of the U.S. invasion of Iraq in March, most Shiite religious leaders in Najaf, including al-Hakim, were put under house arrest. Shortly after the collapse of Saddam's regime, al-Hakim's office went back to work.

Also Monday, the chairman of an Iraqi committee appointed to look into how the country would write a new constitution said a decision on whether members of a constitutional congress would be appointed or chosen in an election would be made within six weeks.

Fuad Ma'sum, head of the 25-member committee, told reporters his group wanted to work quickly ``so that Iraq returns to independence.''

The committee was established by the U.S.-appointed Governing Council, designed as an interim government working under the U.S. occupation coalition.