About a dozen mortar bombs landed in the afternoon in the busy Saadun commercial area in the heart of Baghdad, around the same time multiple rocket fire was heard, AFP correspondents in the city said.

Further details were not immediately available, but the rockets sounded like Russian-made Katyushas, which have a range of around six kilometers (four miles) and are fired from small trucks.

Intense bombing raids in the southern districts of Baghdad were so powerful that they set off alarms in cars parked in the city center. Coalition warplanes swooped several times over Baghdad bringing troops to encircle the city.

US Major Ross Coffman said army troops had fought their way to the Tigris river north of Baghdad, completing a semi-cirle on the western side of the capital. He estimated hundreds of Iraqis had been killed and 25 tanks destroyed.

"The army owns from river to river on the west side," said Coffman, who serves at the Tactical Command Post of the Third Infantry Division, which controls the sprawling international airport on Baghdad's western outskirts.

The United States said Saturday its fighter jets were flying 24 hours a day over Baghdad to protect ground troops in the war to oust President Saddam Hussein.

Faced with the onslaught, Iraqi officials -- including Saddam himself -- have been insisting that they will ultimately prevail and that they have inflicted heavy losses on coalition troops.

Information Minister Mohammad Said al-Sahhaf, who has insisted US forces do not control the airprot, said the Iraqis on Saturday "attacked the enemy with missiles" at the airport.

"We killed 50 soldiers in enemy ranks," he told a press conference Sunday.

In a statement the day before on Abu Dhabi television, Sahhaf had said he believed more than 300 US troops had been killed in the fighting around the airport.

The US Central Command said more than 2,000 Iraqi troops were estimated to have been killed in the incursion, meant as a "poke in the eye" to Saddam to show that US troops could come and go as they pleased.

The debris of a number of Iraqi tanks and other vehicles still littered the side of the main road where the battle took place.

Iraqi officials took journalists to see a destroyed Abrams tank on the side of the highway connecting Baghdad to Kerbala, which they said was destroyed with an anti-tank rocket.

Ahmed Khoder, a member of the special Republican Guard, said five people were inside the tank and all were killed. However, there were no bodies or other clear signs of coalition deaths.

Khoder said that one hour after the fighting, "President Saddam Hussein came to congratulate us and asked us to fight until the end."

Saddam, who was shown on Saturday chairing a meeting of top aides including his sons Uday and Qusay, has recently appeared frequently on television and on Friday, he was seen on a busy Baghdad street to show he is still in control.

In a speech read on television on his behalf Saturday by Sahhaf, Saddam told Iraqis the battered capital was still theirs to save.

"The enemy has concentrated all its forces against Baghdad, which has weakened its power in other parts of Iraq," said the address.

"You must now weaken them (further), deepen their wounds and deprive them of what they have taken of your land, even though it is negligible, in order to reduce their chances and accelerate their defeat."

Ath-Thawra, the mouthpiece of the ruling Baath Party, ran a front-page headline Sunday, "Saddam International Airport turns into graveyard for the invaders." A cartoon in the paper showed US President George W. Bush shooting with an assault-rifle while sitting in a coffin.

Armed paramilitary troops and policemen were heavily deployed in all Baghdad neighborhoods, with more trenches being dug along main roadways.

Sahhaf said Iraq had imposed a 12-hour ban on travel to and from Baghdad starting at 6:00 pm each evening "to prepare our movements and our work to confront the enemy and crush him."

But the city appeared relatively normal, with traffic moving again on the main avenue of the US incursion and public transport running as usual. Most shops were closed, but many men were out on the sidewalk cafes sipping traditional dark tea.

Most of the capital's five million residents have tried to stay with relatives in the city center, perceived as less vulnerable to attack, or moved out to the countryside, mostly to the north of Baghdad.

But the road is not entirely safe. Several Russians were injured Sunday when the convoy evacuating Moscow's ambassador out of Baghdad came under fire, a Russian foreign ministry spokesman said.

SPACE.WIRE