US missiles targeted Saddam’s palaces and family residence, including the home of his elder son Uday, Iraq radio said. The Iraqi Army reported that four of its soldiers were killed and six were wounded in the US-led attacks.

Fire fighters and ambulances drove to the scene but the flames roared out of control and smoke rose high into the night sky.

It was the second round of US attacks after Saddam defied a US ultimatum to leave the country. The previous raid at dawn yesterday targeted the Iraqi president himself and his senior leadership but the results were not clear.

The main offensive was still being awaited here. US officials had vowed a massive assault against Iraqi leaders and soldiers to the point that they would be too dazed and demoralized to resist. That barrage had yet to unfold in its full ferocity.

In Washington, US Defense Secretary Donald Rumsfeld said the initial missile and bombing attacks in and around Baghdad were just a first taste of what would soon be unleashed.

“What will follow will not be a repeat of any other conflict. It will be of a force and scope and scale that has been beyond what has been seen before,” he said.

An Iraqi military spokesman said that a US helicopter had been shot down.

“An American aircraft of the Sikorsky type used in carrying troops and eqipment was downed as it was trying to infiltrate Iraqi airspace to carry out aggressive operations. Long live Iraq,” the spokesman said in a statement.

The Iraqi statement gave no further details. US military officials were not immediately available for comment.

Sikorsky Aircraft Corp. manufactures the Black Hawk helicopter, which is used by US forces to fly troops into combat.

Arab News in Baghdad heard the first explosions at 5.30 a.m., when many Iraqis were performing Fajr prayers in the local mosques. Black smoke billowed from one eastern district. The sound of air the raids came before the sirens were heard. There were explosions in many parts of the city.

“These are opening stages of what will be a broad and concerted campaign,” Bush had earlier said in a televised address to the Americans.

Baghdad retaliated weakly by firing six missiles into northern Kuwait.

A defiant Saddam appeared on state television within hours of the air raids, calling on his people to resist their attackers.

“You will be victorious against your enemies,” proclaimed Saddam, dressed in military garb and black beret. “We will resist the invaders... the devil will be defeated.”

“Unsheath your swords,” he told Iraqis, accusing Bush — “the tyrant of the century” — of committing “a crime against humanity”.

In northern Iraq, the leaders of the two Kurdish factions controlling the area said their forces had taken up defensive lines in their region, which has seen thousands of people pouring in from government-controlled areas.

The limited strikes followed reports from US intelligence operatives, who had been secretly deployed in Baghdad and other parts of Iraq for weeks, tracking the movements of senior Iraqi officials, a US official told journalists.

Following the missile strike, F-117 stealth fighter-bombers unleashed 900-kilogram (2,000-pound) bombs on their targets. US units have been making every effort to encourage Iraqi troops to give themselves up or to show they do not intend to fight back and were expecting to deal on the way to Baghdad with Iraqi forces surrendering en masse.

Armed security and police forces were deployed in Baghdad, particularly around government ministries, state buildings, offices of the ruling Baath Party and Saddam’s various palaces.