US forces closed in on Monday on Baghdad in their bid to topple Saddam Hussein after moving past stiff resistance in southern Iraq and suffering heavy losses in this Euphrates river town.
Field reports said US Marines were racing towards the capital from the southeast, with US Army infantry to the west surging past Najaf, about 160 kms outside Baghdad.
US commanders expressed satisfaction with their forces' progress after four days as they continued to bomb Baghdad and prepared to open a northern front against Saddam's outgunned army.
"I think we are on track," Lieutenant General John Abizaid, deputy head of the US Central Command, said at the US forward command post in Qatar. "We'll arrive in the vicinity of Baghdad soon."
But the going on the ground was tougher than expected.
US Marines supported by Cobra attack helicopters and artillery took on stubborn Iraqi opposition in Nasiriyah, skirting it after what Abizaid called "the sharpest engagement of the war thus far."
He confirmed that some Marines -- "less than 10" -- were killed and others wounded. The BBC quoted US sources as reporting four American dead and 50 wounded in the battle it said pitted 5,000 Marines against some 500 Iraqis.
Fighting continued outside the southern port of Basra as Britain's vaunted Desert Rats faced fierce opposition from Iraqi forces with rocket-propelled grenades, artillery, mortars and machine guns.