4.00pm

UPDATE - US-led invaders seeking to oust Iraqi President Saddam Hussein launched a ferocious barrage on Baghdad's eastern outskirts on Saturday as they prepared to draw a noose of steel around the capital.

Devastating explosions rocked the southeastern districts of Baghdad after a night of relentless bombing aimed at the eastern fringes of the city, Reuters correspondent Hassan Hafidh said.

The attack in the east followed hard on the heels of the capture by US troops on Friday of the city's airport, 12 miles to the southwest of the city centre, the biggest prize yet for US-British forces in the 17-day-old war.

US commanders called in reinforcements to beef up the estimated 1,500 troops at the airport, possibly opening the way for it to be used as a forward base in a battle for the sprawling city of 5 million people.

There was no sign of the "nonconventional" attack on US troops -- "a kind of martyrdom operation" -- threatened by Iraqi Information Minister Mohammed Saeed al-Sahaf on Friday.

A huge armored column of US Marines closed in on Baghdad on Friday, the eastern flank of a pincer thrust on the key target in the war.

"We are going to try to isolate Baghdad," Marine Capt. Matt Watt told Reuters. "We're going to surround Baghdad and start taking chunks out of where the enemy are."

The mood in the capital was grim.

"This is it. This is the final battle. We have no way out. We are facing a reality now. We're confronting the mightiest army in the world. What can we do? Where can we go? We're at a loss," said Nour Khaled, 48, a mother of two.

US military leaders sought to quash any expectations that the end of the war was near, noting that the battle to conquer Baghdad could entail dangerous urban warfare in which their technological edge over the Iraqis would be blunted.

"We know there are forces inside (Baghdad) that have intent to fight. It will take time to gain a degree of control and security," Brig. Gen. Vincent Brooks told reporters.

Iraq sought to rally resistance on Friday by broadcasting television footage of what it said was Saddam touring bomb-damaged Baghdad streets and greeting enthusiastic residents.

The broadcast, which did not make clear when the public appearance took place, sparked speculation in the United States over whether the real Saddam or a double had been shown.

Iraqi television also showed what it said was Saddam reading a statement in which he referred to the downing of a US Apache helicopter on March 24.

CALL FOR RESISTANCE