"We've crossed a bridge and are threatening Baghdad," said Colonel Will Grimsley 1st brigade commander of the Third Infantry Division.

US military sources said the bridge was located 30 kilometres (20 miles) from the Iraqi capital.

After US troops passed through the Kerbala gap earlier Wednesday, the Euphrates was the last major natural obstacle before the final push toward Baghdad.

An AFP correspondent travelling with the US troops said he saw one Iraqi tracked vehicle and a couple of Iraqi trucks lying destroyed on one side of the road leading across the river. A fire could also be seen burning on one river bank.

Machine-gun fire and rounds from 155mm Paladin howitzers were heard nearby while multi-launch rockets arced up into the night sky, he said.

Earlier, the US forces had engaged the Iraqis to prevent them from sending in reinforcements to defend the strategic bridge.

The AFP correspondent was unable to give an exact location under conditions for media accompanying the coalition forces.

SPACE.WIRE