U.S. tanks on Monday edged to within 500 yards of the Imam Ali shrine (search), Iraq's holiest Shiite site, as explosions shook an adjacent cemetery that has been the scene of fierce fighting between American troops and militants loyal to the firebrand Shiite cleric Muqtada al-Sadr (search).

Fighting in Najaf killed two U.S. soldsra and kidnapped his handicapped and ailing 80-year-old father.

"They dragged him on the street in front of the local residents," al-Jazaari said.

He said the gunmen were accompanied by police loyal to al-Sadr and the militants told him his father, Hadi Kudhaiyer al-Jazaari, would only be released if al-Jazaari was willing to take his place in captivity. Al-Jazaari said he would not give in.

Also Monday, police said a Western journalist, Micah Garen (search), and his Iraqi translator, Amir Doushi, were kidnapped as they walked through a crowded market in the southern city of Nasiriyah.

Witnesses said the men were abducted Friday by two men in civilian clothes and armed with Kalashnikov assault rifles, according to police Capt. Haidar Aboud said.

Adnan al-Shoraify, deputy governor of Dhi Qar province, said Garen was a journalist with U.S.-French citizenship who worked for the U.S.-based Four Corners Media and was working on a project involving antiquities near Nasiriyah.

Armed assailants also attacked a convoy of Turkish trucks on its way back from delivering supplies to U.S. forces in Baghdad and took two drivers hostage, their company said Monday. The two men were abducted outside the northern city of Mosul, said Oktay Gorgun, an official with the trucking company.

The U.S. military estimates hundreds of insurgents have been killed since clashes broke out in Najaf on Aug. 5, but the militants dispute the figure. Eight Americans have been killed, the military said.

Al-Jazaari said 40 police have been killed and he accused the militants of torturing, maiming and burning the bodies of some. At least 19 policemen, including his nephew, were beheaded, he said.

Another officer was found Monday with his throat slit in his car in the city center, said Brig. Amer Hamza, the deputy police chief. He blamed the militants for the killing.

Iranian Foreign Minister Kamal Kharrazi asked U.N. Secretary-General Kofi Annan to intervene to help stop the fighting, the official Islamic Republic News Agency reported Monday.

"Americans once again made a grave blunder in calculating developments in Iraq and provoked the sentiments of the Iraqi people through resorting to the use of force," IRNA reported Kharrazi told Annan in a telephone conversation.

Saudi Arabia's Cabinet also called for "a greater role for the United Nations in efforts to stop the bloodshed," the official Saudi Press Agency reported.

The continued Najaf fighting has undermined the Iraqi interim government in the eyes of Shiites, angered by the sight of U.S. troops firing around some of their holiest sites.

It also dominated Iraq's national conference Monday in Baghdad, with tribal and religious leaders deciding to send 60 delegates to the holy city to persuade al-Sadr to call off his fighters.

Fighting Sunday apparently caused minor damage to the outer wall of the shrine compound — where the militants are holed up — ripping off some tiles and leaving some holes. U.S. commanders, who have taken the lead in the Najaf fighting, have issued strict orders to keep the shrine out of the line of fire.

An armed group also claimed it had captured an Iraqi intelligence operative and would kill him if the military operation in Najaf continues, according to a video shown early Tuesday on the pan-Arab Al-Jazeera television station. The video showed the captive, identified as Osama Abdul Jawad, standing between two armed masked men.

In other developments Monday:

— Two civilians were killed and four wounded when a mortar hit their house in Baqouba, 35 miles northeast of Baghdad, said Ali Hussein, a medic at the main hospital there. It was not known who fired the mortar, but insurgents frequently clash with U.S. troops and Iraqi security forces in the city.

— A roadside bomb in Baqouba wounded three members of the Iraqi National Guard, said guardsmen Zuhair Abdul-Kareem, who was injured in the blast.

— A U.S. tank in Baghdad's Shiite stronghold of Sadr City was ambushed, but the crew escaped with only minor injuries, said Maj. Philip Smith, deputy spokesman for the 1st Cavalry Division.

— Two Lebanese truck drivers, Taha al-Jundi and Khaldoun Othman, who were kidnapped two weeks ago were released, Othman's brother Waleed said Monday.

— U.S. warplanes bombed a house in Fallujah, west of Baghdad, but caused no damage or injuries, residents said.

— Maj. Muayad al-Hardan, an official with the Anbar provincial police, was shot to death as he drove his police car in the city of Ramadi, police 1st Lt. Ibrahim Mohammed said.