"The dagger is clearly pointed at the heart of the regime and will remain pointed at it until the regime is gone," Brigadier General Vincent Brooks told a news conference at US Central Command's forward base in Qatar as forward units advanced to within 50 miles (80 kilometers) of Baghdad.

Brooks said marines had "destroyed" the Baghdad Republican Guard division after a major battle to the southeast while the US Army's 3rd Infantry Division punched its way northeast towards the capital after passing through a vital gateway to Baghdad.

"The First Marine Expeditionary Force attacked the Baghdad Division near the town of Al-Kut and has crossed the Tigris River. The Baghdad Division has been destroyed," he said.

But an Iraqi military spokesman insisted the division "has not suffered any losses and is ready to confront the enemy".

"The Baghdad division maintains its cohesion and has a morale of steel," he told AFP.

A Centcom spokesman told AFP earlier that US troops attacked the Baghdad, Medina and Nebuchadnezzar Republican Guard divisions south of the capital, while air strikes targeted the Adnan division to the north.

An AFP reporter travelling with the US 3rd Infantry Division reported passing through the strategic "Karbala gap" passageway to the west of Karbala, 80 kilometers (50 miles) south of Baghdad.

"This is it, the last push," said Major Maurice Goins, operations officer of the 1st brigade, before the attack near Karbala.

Marines cut off the Baghdad Republican Guard division during a major battle on the approach to Al-Kut after crossing the Tigris, a senior officer told AFP.

"The final push to Baghdad is now on," he said.

"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.

The main road from Al-Kut to Baghad had been cut off as US planes bombed targets within the city.

The 3rd Infantry met only "disorganised" resistance as they drove through the narrow desert strip between the Euphrates and a large lake east of the city, said first brigade commander Colonel Will Grimsley.

A-10 Thunderbolt planes could later be heard bombing Iraqi positions to the northeast of Karbala as the troops continued to push forward, declining to enter the Shiite holy Muslim city itself.

In the southern city of Najaf, coalition troops came under fire from the Ali mosque, a revered shrine in Shiite Islam, a US military spokesman alleged.

"We'refusing to return fire at the mosque," Ensign David Luckett added.

Iraqi Information Minister Mohammed Said al-Sahhaf for his part accused the US-led coalition of trying to destroy holy Shiite shrines in Najaf and Karbala.

The Centcom official said troops from the Adnan division, based in Saddam's heartland of Tikrit to the north of Baghdad, were rushing to support its sister divisions to the south.

"Coalition aircraft are interdicting the Adnan division as it goes south from Tikrit to Baghdad to reinforce," he added.

However a message issued in the name of the Iraqi president Wednesday, insisted that the regime had so far committed just a "third" of its forces at most to the fighting.

"We have only deployed a third of our army, or even less than a third," said the message read for Saddam by an announcer in military uniform on Iraqi satellite television.

In Baghdad itself, intensive bombardment was heard late Wednesday afternoon and plumes of smoke rose from several parts of the capital.

The bombardments picked up again at 5:00 pm (1400 GMT). Columns of smoke rose in particular from Saddam's Republican Palace compound in the heart of the capital.

Fighter jets from the USS Kitty Hawk also pounded an Iraqi intelligence facility in the besieged southern city of Basra with 2,000-pound (900-kilogram) bombs, the military said Wednesday.

Meanwhile in the north, Kurdish rebels advanced on two roads towards Mosul on Wednesday after Iraqi troops fell back on Iraq's third city overnight.

Sahhaf said 10 people had been killed and nearly 90 people wounded in Baghdad on Tuesday, and 14 killed and nearly 100 wounded in other parts of the country.

burs-co/jmm

SPACE.WIRE