The U.S. Marines entered Baghdad on foot Monday after incurring heavy fire on the city's outskirts. As the U.S. troops moved toward the city center, Iraqi civilians hid inside their homes.

The Marines from the 3rd Battalion 4th Marine crossed into Baghdad about half an hour after they had come under Iraqi fire at a bridge spanning a canal at the southern edge of the city.

Four or five Marines died after an artillery shell hit their armored troop carrier, according to Lt. Col. B.P. McCoy.

The Iraqis had tried to make the bridge impassable by blowing out a span, digging out the embankment under the bridge and rigging it with explosives. Marines had taken control of the bridge Sunday but were unable to cross over until they had rendered it safe for light vehicles.

After the armored vehicle was shelled at the bridge, which crosses the canal on Highway Six into Baghdad, Marines grabbed metal debris Monday and threw it across the bridge to plug the hole. They then ran across, leaving their vehicles behind.

One Iraqi fighter in civilian clothes was sprawled on the bridge.

Two companies of the 3rd Battalion, 4th Marines then spread about a third of a mile apart, trying to secure the area so repairs or a pontoon bridge could be built and their vehicles could be driven across.

Burned vehicles and bodies were strewn across the road in the deserted area in southeastern Baghdad. Fires burned throughout the neighborhood of sand-colored houses and date palm groves.