U.S. and Shiite Muslim militia forces agreed to withdraw from Shiite holy places south of the capital Friday, renewing a cease-fire despite an attack that killed five U.S. soldiers and wounded five others in Baghdad.

Iraq's new interim prime minister, addressing the nation in a televised speech for the first time since his appointment last week, meanwhile called on Iraqis to help defeat terrorism and vowed to take steps to halt the influx of foreign fighters into the country. But he acknowledged that U.S. and other foreign troops would be needed to maintain security after a transfer of political power to the interim government on June 30.

The statements by Ayad Allawi, who was named interim prime minister by a U.N. special envoy, came as the U.S. military announced the capture by Iraqi police of a top aide to Abu Musab Zarqawi, a Jordanian with links to the al Qaeda terrorist network and the suspected mastermind of numerous attacks in Iraq.

A U.S. military statement identified the captive as Omar Baziyani, a "known terrorist and murder suspect" who has ties to "several extremist terrorist groups in Iraq." The statement said the capture of Baziyani May 30 "removes one of Zarqawi's most valuable officers from his network." No details of the capture were given.

Nor was there much information on the attack that military officials said killed five U.S. soldiers and wounded five others around midday in the eastern part of the capital. The deaths and injuries were attributed to an explosion from a powerful roadside bomb that destroyed the soldiers' vehicles while they were on patrol. The 10 soldiers were members of Task Force Baghdad, a unit mainly composed of troops from the 1st Cavalry Division based at Fort Hood, Texas.

The attack on the edge of the Baghdad slum known as Sadr City, a stronghold of militiamen loyal to a radical Shiite Muslim cleric, came several hours after a U.S. Army patrol was fired upon Friday morning in the same general area. A U.S. military official said that in the earlier incident, the U.S. soldiers exchanged fire with gunmen who attacked them with rocket-propelled grenades and assault rifles. The official said there were no known casualties on either side in the first incident.

The four deaths brought to 600 the number of American troops killed in action in Iraq since U.S. forces invaded in March last year, the Reuters news agency reported. In addition, 217 U.S. troops have died in noncombat incidents.

In another incident about 18 miles north of Baghdad, five persons were reported killed when a roadside bomb disabled their civilian vehicle and unknown assailants came up and fired into it. The five were reported to be foreigners, but their identities were not immediately known.

South of the capital, U.S. forces and members of the Mahdi Army, a militia loyal to radical Shiite cleric Moqtada Sadr, agreed to withdraw from the Shiite holy city of Najaf and nearby Kufa. Under the accord, which essentially renewed a cease-fire agreement reached last week, security in sensitive areas around Shiite holy sites in the two cities is being turned over to Iraqi police, U.S. and Iraqi officials said.

It was not immediately clear whether the latest agreement would be any more effective than the previous one.

"All fighting forces, the coalition forces and the al-Mahdi Army militia should leave the two holy cities and not allow any of their elements to enter again," said Adnan Zurufi, the governor of Najaf Province, in announcing the accord. He called the arrangement "an Iraqi solution to the problem."

Col. Brad May of the U.S. Army's 2nd Armored Cavalry Regiment said U.S. forces would move "to the periphery of these sensitive areas" of Najaf and Kufa, allowing Iraqi police to move in, the Associated Press reported. May said the sensitive areas were the Imam Ali Shrine in Najaf and the Kufa mosque.

Sadr, who launched an uprising against U.S. occupation forces in April after his newspaper was shut down and a top aide arrested, made no mention of the deal in a statement read on his behalf in the Kufa mosque. Instead, the statement denounced the new interim Iraqi government as a creature of "the occupying power" and said that nothing less than an elected government was acceptable.

In his televised speech, Allawi, a secular Shiite who opposed former president Saddam Hussein from exile and served on the U.S.-appointed Iraqi Governing Council that was dissolved last week, said it was "a duty of all Iraqis" to fight terrorism. He said the new interim government would tighten controls on the entry of foreigners into Iraq in an effort to prevent the influx of fighters from abroad.

"The flow of terrorists . . . through our borders will stop," Allawi said.

He also announced that the newly appointed interim president, Ghazi Yawar, would attend next week's Group of Eight meeting in the United States to "contribute to the defeat of economic terrorism that criminals are trying to inflict on our beloved Iraq."

Allawi said he plans to meet next week with an Iraqi special tribunal that has been established to try Hussein and other members of his ousted government for alleged crimes against Iraqis during Hussein's three decades in power.

Branigin reported from Washington.