"The final push to Bagdad is now on," said the senior officer.

"The Baghdad division of the Republican Guard is irrelevant. The 3rd and 4th divisions of the Iraqi army are in the bag."

He said Iraqi soldiers were "voting with their feet" and fleeing the US armour as it advanced near Al-Kut, around 150 kilometres (90 miles) southeast of the Iraqi capital.

Marine units had squeezed Al-Kut from the south and west, cutting off the main road to Baghdad and trapping defenders in and around the town.

As the sun fell on the battlefield the exent of the coalition air bombardment became clear, with huge flashes lighting up the sky over the city almost constantly.

Jets and Cobra attack helicopters were involved in the attacks and were meeting limited anti-aircraft fire from Iragi gunners on the ground.

One huge explosion created a massive black cloud which covered the city and brought cheers from the marines watching from the outskirts of the town.

"I don't particularly like the Republican Guard but you have to feel some sympathy for them when you know what they're going through now and what they're going to go through," said one sergeant as he watched the airstrikes.

"It's relentless."

US planes were bombing Iraqi positions inside Al-Kut as the marines regrouped for more fighting during the night.

Medics were seen moving toward the front in preparation for casualties, which had been light in the first phase of the battle.

At US Central Command headquarters in Qatar, US Brigadier General Vincent Brooks also told a press briefing, "The Baghdad Division has been destroyed," but an Iraqi military spokesman strongly denied it.

The division's commander, who was not named, told Iraqi televsion later Wednesday that 17 of his men had been killed and 35 wounded.

"The command is intact and we are ready to confront the enemy wherever he may be," the general said.

SPACE.WIRE