U.S. forces are holding off on a planned offensive against Shiite militants in Najaf -- to give Iraqi security forces time to train for the assault.
The operation is being closely coordinated with the Iraqi government. In fact, a U.S. Marine spokesman says Iraq's interim prime minister is making the "final decision" on timing for the offensive.
It's not known whether commanders are planning a raid into the Imam Ali Shrine -- a move that could enrage Iraq's Shiite majority and Shiites worldwide.
A raid carried out by Iraqi security forces may be seen as less upsetting to Shiites. But Iraqi troops had been criticized as being inadequately trained or armed.
In other recent developments:
In Najaf, fighting persisted in the vast cemetery near the city's holiest site, the Imam Ali Shrine, where U.S. commanders say Mahdi Army militiamen loyal to radical Shiite cleric Muqtada al-Sadr have been holed up.
Gunbattles between militants and coalition forces in two other southern cities killed 18 people.
Ibrahim al-Jaafari, Iraq's interim vice president, called on the U.S. troops to withdraw from Najaf.
"Only Iraqi forces should stay in Najaf, these forces should be responsible for security and should save Najaf from this phenomenon of killing," al-Jaafari told Arab TV network Al-Jazeera from London on Wednesday.
Meanwhile, more than 300 people marched through the streets of the holy city, demanding an immediate halt to fighting.
CBS News' Steve Kathan reports the demonstrators also called for the resignation of Najaf's governor and the withdrawal of U.S.-led multinational forces from the city.
The top health official in Najaf, Falah al-Mahani, said the deteriorating security situation was causing "a real catastrophe" for the health services.
"Ambulances are prevented from reaching the injured people by the clashing parties. Our staff are not able to reach their hospitals. We are paralyzed," he said, adding that the fighting injured 18 members of his staff.
Sporadic explosions could be heard elsewhere in the city. U.S. Marine Maj. David Holahan said Mahdi Army militants attacked three police stations Tuesday, two with small arms fire, one with eight mortar rounds.
"I hope that you keep fighting even if you see me detained or martyred," al-Sadr said in a statement Wednesday. "I thank the dear fighters all over Iraq for what they have done to set back injustice."
To control movement in Najaf, Iraqi police and national guards blocked roads that connect the city's northern and southern parts Wednesday.
The U.S. military has estimated that hundreds of insurgents have been killed in Najaf since fighting began Thursday, but the militants dispute that. Five U.S. troops have been killed, along with about 20 Iraqi officers.
The fighting has plagued other Shiite communities across Iraq.
In Kut, 100 miles southeast of Baghdad, Iraqi police fought off attacks from the Mahdi Army at the town's central police station and other government offices. The fighting killed four people and wounded 20 others said Dr. Falah al-Bermany, a local health official.
"We gave orders to our forces to shoot anyone who gets near government buildings," said Mohammed Ridha, Kut's governor.
Overnight clashes between insurgents and British forces in the southern city of Amarah killed 14 people and injured 42, according to the Health Ministry. Local officials said many of the killed and injured were militants.
In the fighting, British forces attacked positions that militants were using to attack patrols and bases with rocket-propelled grenades and mortars, Maj. Ian Clooney, a British spokesman, said. The British suffered two minor casualties.
During the day Wednesday, British tanks were patrolling the major roads in Amarah, while Mahdi Army militants walked through the alleys, witnesses said.
In Baghdad's Sadr City neighborhood, groups of three to five Mahdi Army militants attacked a district council hall repeatedly Tuesday with mortars, gunfire and rocket-propelled grenades, clashing with U.S. and Iraqi forces, said U.S. Capt. Brian O'Malley of the 1st Brigade Combat Team.
One person was killed and 18 wounded in the skirmishes, the Health Ministry said. Other clashes in Baghdad killed seven people and wounded 11 others.