BAGHDAD — Baghdad was kept awake well into the early hours of Saturday after the United States pounded the city with waves of air strikes that turned vast sections of Saddam Hussein’s Iraqi capital into an inferno.

Countless bombs and missiles smashed into targets across this ancient city, sending towers of flame and smoke into the skies above as the US began the “shock and awe” assault it had been threatening to topple Saddam from power.

Saddam’s Republican Palace, symbol of his iron grip on Iraq since 1979, lay in flames.

“The regime is starting to lose control of their country,” US Secretary of Defence Donald Rumsfeld said in Washington. “What is taking place today is as targeted an air campaign as has ever existed.”

Ambulances wailed through the streets while Iraqi anti-aircraft gunners fired back against the ferocious onslaught, on day two of a war the United States and Britain will not conclude until Saddam’s 24-year reign is brought to an end.

The explosions were too numerous and too fast to count. A US naval commander at sea in the Gulf said 320 cruise missiles had been fired.

Rumsfeld called it “a humane effort to do what is necessary to reduce this threat against our country and that region and to eliminate a regime that has killed hundreds of thousands of human beings”.

He said the goal was “to end the regime of Saddam Hussein by striking with force on a scope and scale that makes clear to Iraqis that he and his regime are finished”.

Air raid sirens gave residents just a few moments’ warning before the first missiles slammed into the city around 9:00 pm (1800 GMT). Satellite television brought the fearsome assault live to viewers around the globe.

Iraqi Defence Minister Sultan Hashem Ahmad was holding a press conference in the centre of the city when the room was shaken by an intense wave of explosions whose roar nearly drowned him out.

But the defiant minister vowed: “No force in the world will conquer us because we are defending our country, our principles and our religion. We are, no doubt, the victors.”

It was the first time since the war began that AFP reporters in the Iraqi capital had been able to see US fighter planes flying over Baghdad.

After what had been a relatively calm weekly day of rest, with children playing football in the streets and their elders shopping for essentials, the first missiles crashed into this city of five million anxious residents.

More than five hours later missiles were heard landing on the outskirts of Baghdad early Saturday, shortly after air raid sirens went off in the Iraqi capital, according to the Qatari-based satellite channel Al-Jazeera.

Iraqi Information Minister Mohammed Saeed Al-Sahhaf, speaking on Al-Jazeera, said a guest house and a former royal palace had been left in ruins.

“This criminal (ordered) the destruction of the Az-Zuhur (Flowers) palace, a former royal residence turned museum … and the guest palace, dubbed Peace Palace,” he said, referring to Rumsfeld.

Sahhaf did not say if the two destroyed buildings, including the palace that formerly housed the monarchy toppled in a 1958 coup, were inside Saddam’s presidential compound, which was hit on the second night of the US-led war aimed at unseating the Iraqi leader.

But AFP correspondents in Baghdad reported that the guest palace is located inside the compound while the Az-Zuhur palace lies in a southern suburb close to the capital’s international airport.

At least six missiles appeared to have hit the compound after reporters said war planes had started up their engines and roared off from a US aircraft carrier, part of a huge US military presence at the ready, waiting in the Gulf.

Saddam has scorned US calls for him to evacuate, and his government had announced earlier yesterday that it would award cash prizes to Iraqis who managed to capture US soldiers or shoot down their aircraft.

But on a day when US and British invasion forces were making their way through southern Iraq, taking hundreds of Iraqi soldiers prisoner in the push toward Baghdad, the United States made no secret of its aerial firepower.

“The weapons that are being used today have a degree of precision that no one ever dreamt of in a prior conflict,” said Rumsfeld, who insisted the United States was doing all it could, not to hit civilians.

Iraq charged earlier that US air strikes had intentionally targeted civilian areas, and that 37 civilians were wounded in pinpoint bombardments on Thursday evening.

Meanwhile, an entire division of the Iraqi army, numbering 8,000 soldiers, yesterday surrendered to coalition forces in southern Iraq, Pentagon officials said.

Iraq’s 51st Infantry Division surrendered as coalition forces advanced toward Basra, Iraq’s second largest city. The mechanised division had about 200 tanks before the war, according to independent analysts and US officials.

The 51st was one of the better equipped and trained in Iraq’s regular army forces and was the key division protecting Basra, a major transportation and oil shipment hub on the Shatt al-Arab waterway that leads to the Persian Gulf.

The division also was important to Saddam Hussein’s government for keeping Shiite Muslims — the majority in southern Iraq — from rebelling against Saddam’s largely Sunni government.

The division was the largest single unit to surrender en masse yesterday, a day that saw hordes of Iraqi troops give themselves up — in some cases, to journalists accompanying US units. US forces advancing across southern Iraq often found Iraqi tanks and other weapons abandoned in the desert.

Many of the surrendering Iraqis were demoralised and poorly equipped, with some wearing T-shirts and carrying worn Kalashnikov rifles.

“I kind of felt sorry for them,” said one US military official in southern Iraq, speaking on condition of anonymity. “A lot of them looked hungry. They haven’t been fed in a while.”