On Thursday, the 15th day of the invasion, aerial bombardment of the city seemed heaviest. There were claims and counter-claims as ground forces began what was said to be their serious advance on the capital.

While Major Randi Steffy, a spokeswoman for the US Central Command in Qatar said that US forces were in the vicinity of Baghdad, just “outside the airport”, Iraqi Information Minister Mohammed Sa'id al-Sahaf dismissed the claims, countering that US troops were “not even 100 miles” from Baghdad.

On Thursday afternoon, Baghdad's Saddam International Airport was still under the full control of Iraqi authorities, according to reporters on the scene. They added that no bombing or fighting was visible at the airport, which lies 20 km southwest of the city center.

The airport is safe," its manager Mu'waffaq Abdullah al-Jaburi told the reporters who were escorted there by the Iraqi information ministry. Al Jaburi joked, "maybe the Americans occupied another airport in the desert."

A statement from President Saddam Hussein, read out on state television, promised viewers that Iraq's forces would never let the capital be taken.

“Many thousands of soldiers are defending the homeland ... and they will not allow them to go into Baghdad without defeating and repelling them.” In his televised statements, the Iraqi President claimed that barely a third of Iraq's forces had so far been engaged in battle.

At a North Carolina military base, President George Bush did his best to focus and boost troop morale: "The course is set. We're on the advance. Our destination is Baghdad, and we will accept nothing less than complete and final victory."

US officers on the battlefield, in the Iraqi desert, said that 500 of Iraq's fighters were killed in clashes with US forces for a key bridge some 30 kilometres southwest of the capital, while other US soldiers were just half that distance from downtown Baghdad.

Major General Buford Blount, commander of the 20,000-strong US infantry division outside the city, claimed that the US military now controlled the southern approaches to the capital.

- Fierce resistance

Strong resistance, from the leadership's elite Republican Guard, was said to be in full swing outside the capital, although details remained hazy. General Blount said that his troops took on elements of the armoured Medina and Hammurabi divisions of the Guard that had already been hit by days of US air strikes.

"The air force killed most of their tanks before they (US troops) got there," he told reporters. Earlier in the day, the US forces raided a presidential palace 90 km outside of Baghdad, capturing no regime officials but seizing documents, a US commander said.

Meanwhile, the US army has continued its attempts to open a front from northern Iraq. Al Jazeera's correspondents on the ground and other military observers in the Arab world confirm the fact that so far, neither US or British forces have secured control of a single Iraqi city.

Waddah Khanfar, Al Jazeera's correspondent in the North, reported fierce and intermittent exchange of fire between the US troops and Iraqi soldiers. “Observers doubt whether the US will succeed in opening a new front in the north, since they do not have appear to have the right armament for the job,” Khanfar said.

Quoting eye-witness accounts in the town of Aski Kilik which links Arbil to the northern city of Mosul, Khanfar added that US warplanes have kept up their bombing from the skies, to clear the path for Kurdish fighters. In what looked like a tactical move, the Iraqi army has now withdrawn from some positions in Bardarsh region, heading for the mountains on the outskirts of Mosul. The vacated region has been taken over by rebel Kurdish fighters opposed to the Hussein government in Baghdad. --- Al Jazeera with agency inputs