Hundreds of protesters blocked U.S. Marines from entering Kut's city hall Tuesday to meet a radical anti-American Shiite cleric who has declared himself in control here, military officials said.

About 20 Marines from Task Force Tarawa decided against trying to enter the building after being confronted by 1,200 protesters, said Lt. Col. Jean Malone, deputy operations officer for the 2nd Marine Expeditionary Brigade.

The protesters were shouting "No, No Chalabi!" -- referring to Ahmed Chalabi, the leader of the Pentagon-backed Iraqi National Congress opposition group.

Many Iraqi opposition leaders fear the United States is trying to force Chalabi on them as leader of a new Iraqi administration.

Said Abbas, a cleric who American officers claim is Iranian-backed and supported by only 10 percent of the local population, seized city hall before coalition forces entered Kut last weekend.

Military officials say he has been preaching anti-American statements in local mosques. Col. Ron Johnson, deputy commander of Task Force Tarawa, said U.S. troops wanted to meet with Abbas to tell him "there is more than just one leader in the region."

However, after the Marines were turned back by the morning protest, two men who claimed to be Abbas representatives came to the makeshift military headquarters in Kut and said they weren't in control of the protesters and they had nothing against the American presence, Malone said.

"Clearly, the U.S. Marine Corps is in control of the city," Malone said. "If we'd gone to kick him out, he'd be out."

Marines in Task Force Tarawa are still awaiting orders from their superiors on what to do in the rapidly changing situation in southern Iraq as large-scale fighting has ended, Malone said.

"We're not exactly sure what our responsibilities are," he said. "We'd like to see a stable and secure city."

Johnson said there were no immediate plans for Marines to arrange a meeting of town elders to decide on their government. He also expressed worries about security in Kut, saying there were a lot of small arms spread through town.

The former regional police chief told Marines on Tuesday he wanted to put his officers back on patrol and allow them to be armed, Malone said. The city has avoided the large-scale looting seen elsewhere in the country, but there has been violence against former symbols of the regime. Gunfire is heard often at night.

The U.S. military is considering the police chief's request, but Malone said commanders are being cautious about the trade off between providing immediate stability and avoiding the risk they "put someone back in power who really shouldn't have power."