Soldiers of the 82nd Airborne Division fired on suspected Iraqi positions on the outskirts of this Euphrates River city tonight during a second day of clashes here between U.S. Army forces and Iraqi military and militia groups.

Explosions periodically lit the skies as U.S. soldiers engaged the Iraqis with small arms, mortars and 2.75-inch rockets fired from OH-58 Kiowa helicopters.

The firefights occurred along the eastern and western edges of this city, 150 miles south of Baghdad, when occasional attacks by Iraqi forces brought return fire from U.S. forces, officials said.

"In most cases it's accidental contact," said Maj. Peter Wilhelm, a spokesman for the 2nd Brigade, "with neither side really expecting it."

Two battalions from the 82nd Airborne have met resistance from what commanders described as a mix of Iraqi army units and paramilitary groups loyal to Saddam Hussein's government. The battalions, with tank support from a company from the 1st Armored Division, tried to block vehicle and foot traffic into the city of about 140,000 people to prevent the Iraqis from bringing in reinforcements and replenishing ammunition.

"There's a combination of different kinds of forces we're seeing," said Col. Arnold Bray, commander of the 2nd Brigade. "Everyone from [paramilitary groups] to the regular army to the Republican Guard."

Bray estimated that at least "some tens" of Iraqis were killed today and an unknown number taken prisoner. Division commanders estimated an additional 14 Iraqis had been killed Saturday and three taken prisoner.

No U.S. troops were reported killed during the two days of fighting, although an infantryman was wounded today when he was hit in the face by rifle fire, a division spokesman said.

In today's fighting, Bray said, the Iraqi forces fired at the U.S. troops from civilian areas, including a playground where children were present.

"They put mortars right inside the playground," Bray said. "I watched them do it. There were children right in front of them."

Throughout the afternoon, a large cloud of black smoke hung over the city's eastern edge, where the Kiowa helicopters fired on a warehouse that Bray said he believed housed seven Iraqi fighters. He speculated the billowing smoke could have been caused by ammunition stored inside.

Taking control of cities near supply routes serving the U.S. forces moving toward Baghdad became a priority after a series of ambushes along the routes in south and central Iraq. Commanders with the 82nd Airborne said more than 1,000 Iraqi paramilitary fighters are believed to be in Samawah with an unknown number of Iraqi troops.

Spec. Joseph Barnhart, a gunner with the 1st Armored Division, which supported today's operation with 14 Bradley Fighting Vehicles, said the Iraqi forces appeared fearless despite being overpowered by U.S. weaponry.

Small numbers of paramilitary forces, described by Barnhart and others as wearing black or white robes, approached U.S. troops on foot and in pickup trucks with AK-47 assault rifles. He said two Iraqis attacked his vehicle, then ran into a metal shed. He fired 25mm shells at them, setting the shed on fire.

"If you're in a pickup truck, would you drive toward one of these Bradleys with only a couple of rifles and a couple RPGs [rocket-propelled grenades]?" said Barnhart, 24, from Seattle. "It doesn't make a lot of sense to me."

Most civilians in the city stayed indoors, according to several soldiers involved in the battle.

"I think the people are really scared in there, is my personal opinion," said Maj. Dale Ringler, 39, of Bellevue, Neb., who drove one of the Bradleys.

Wilhelm, the brigade spokesman, said the division took a family into protective custody after they approached the Americans and indicated they wanted to surrender. A woman in the family told the soldiers her husband had been captured by the Americans, Wilhelm said, and she said paramilitary forces had warned them that this would bring a death sentence for the family.