A US tank also shelled the Baghdad hotel used by many journalists covering the conflict, killing two cameramen and wounding three other media personnel.

Two Abrams tanks rolled out of the northern entrance of the presidential palace compound, which US forces partially occupied the day before, and took up position on the adjacent Al-Jumhuriya bridge.

The move sparked exchanges of fire between US forces and lightly-armed Iraqis holed up on the east bank of the Tigris.

Pro-Saddam militiamen clad in T-shirts, jeans and sneakers stationed themselves behind a wall after setting up roadblocks with sandbags, but their Kalashnikov rifles and anti-tank rockets were no match against US firepower, and the tanks pressed on.

Information Minister Mohammed Said al-Sahhaf claimed however that the Iraqis had "imprisoned" US troops inside their tanks.

"They are going to surrender or be burned in their tanks," Sahhaf said when asked if it was not time for Baghdad to give up.

He was speaking outside the Palestine Hotel, which houses most foreign journalists still in Baghdad, minutes after it came under US bombardment.

A Ukrainian cameraman working for Reuters, Taras Protsyuk, 35, was killed and three other staff members were wounded, the British news agency said in London.

Spanish cameraman Jose Couso died in the same incident, his employer Telecinco said.

General Buford Blount, commander of the US 3rd Infantry Division, said a US tank was "receiving fire from the hotel, RPG (rocket-propelled grenade) and small-arms fire, and engaged with one tank round. The firing stopped."

But footage shot by France 3 television showed the tank gun pointed for at least two minutes at the hotel before it opened fire, and without any shots being heard fired at the tank.

Elsewhere in Baghdad, the correspondent of Qatar-based Al-Jazeera, Tareq Ayub, a 34-year-old Jordanian of Palestinian origin, died after the station's office was hit by a missile.

While the United States said it was not targeting journalists, two media organs it has openly wanted to shut down, Iraqi state television and radio, both went off the air Tuesday.

Baghdad's satellite television channel went down on Sunday night and Youth television, run by Saddam's elder son Uday, has failed to broadcast since a missile struck the information ministry at the end of March.

US officials have charged that Iraqi state-controlled media -- known for their incessant victory speeches and denial of any coalition advances -- have been a key factor in preserving Saddam's control.

From 7 pm (1500 GMT) onwards, however, Baghdad turned into a ghost town, with even armed fighters off the streets of large parts of the city.

AFP correspondents reported sporadic explosions on the southern rim of the city, but there was no fighting around the Republican Palace and the city centre was eerily quiet.

Iraqi fighters who had been heavily deployed across the city since the outbreak of the US-led assault on the country March 20 had all but dissappeared from the eastern bank of the Tigris river.

Sandbag reinforcements on street corners once providing shelter to armed militiamen were empty.

No guards were standing in front of police stations and neighborhood headquarters of the ruling Baath party.

Earlier a US A-10 Thunderbolt ground attack aircraft made three firing passes over the presidential palace, while Apache combat helicopters made their first appearance over the city, firing on targets in the southern sector.

An A-10 was hit by a missile over Baghdad soon afterwards and crashed, but it was not known if it was the same aircraft. The pilot ejected and was rescued.

Meanwhile, the International Committee of the Red Cross said a water purification station in northern Baghdad was hit overnight by a missile, putting at risk supplies to the major suburb of Saddam City.

The lack of water and electricity has also hit the Saddam Medical Center on the east bank of the Tigris river, with six of its 27 operating theatres out of service.

There was new speculation on Saddam Hussein's fate, as a US official in Washington said a building hit Monday in Baghdad's Al-Mansur district could have been housing the Iraqi leader and his two sons, Uday and Qussay.

"I don't know whether he (Saddam) survived," US President George W. Bush told reporters after a two-day summit in Northern Ireland with British Prime Minister Tony Blair.

A US Central Command spokesman in Qatar said four 2,000-pound (900-kilogram) satellite-guided bombs were dropped.

SPACE.WIRE