A series of explosions shook Baghdad during the morning as the southern, western and northwestern outskirts were bombarded, an AFP correspondent reported.

The bombardments hit as a US defence official said US ground troops were taking on the Republican Guard in a first major battle south of Baghdad.

In the push towards the capital, US forces were "fully engaged" for the "first time" with Republican Guard troops near Karbala, about 80 kilometers (50 miles) to the south.

Saddam's main presidential compound in the city had come under intensive attack from coalition bombs before dawn, as it had for the previous two days, AFP correspondents reported.

The latest attack on the riverside Republican Palace occurred at 3:05 am (0005 GMT), 10 minutes after a bridge in the east of the city was targeted.

Saddam's call to arms was was read on state television on night 13 of the war to topple him from power, in an appeal to international fury over the latest killings of women and children.

But US President George W. Bush blamed Saddam for civilian deaths, as US and British forces continued both the air blitz and a grinding, bitterly fought ground campaign pushing northward towards a showdown in Baghdad.

In a speech read by Information Minister Mohammed Said al-Sahhaf, Saddam said jihad was a "duty" for Arabs and Muslims and branded the US-led war an assault on "religion, property, people and honour."

"Fight them in every location as you are doing today, and don't give them a chance to catch their breath until they pull out of Muslim land," the speech said. "Hit them, fight them! They are evil aggressors."

US commanders say they do not know if Saddam, who has almost always steered clear of live television during his 24-year rule, remains alive after the thousands of air strikes which have pounded Iraq since March 20.

Both London and Washington said Saddam's non-appearance on television raised "questions" about his fate.

Iraqi officials have scorned any suggestion he may be dead or hurt, while state television regularly shows him meeting with his inner circle. But it is not known, as always in Baghdad, if the footage is pre-recorded.

The rallying cry came after at least 48 more civilians, many women and children, were reported dead in the round-the-clock aerial assault that has been pummelling Baghdad and surrounding areas.

In the farming town of Hilla south of the capital, the local hospital director said 33 people were killed and more than 300 wounded in a bombing raid Tuesday.

A spokesman for the International Committee of the Red Cross described the "horror" at the hospital and said: "There were dozens of smashed corpses."

An AFP reporter saw what appeared to be the component devices from cluster bombs, equipped with small parachutes, covering a large area in the town, which lies 80 kilometres (50 miles) south of Baghdad.

Another AFP reporter with US ground troops assaulting the area said the attack had been backed up by air raids from B-52 bombers.

Razek al-Kazem al-Khafaji sat inconsolably among 15 coffins, bearing what he said were the bodies of his family killed Monday night by a US rocket fired from a helicopter on their pickup truck.

He told AFP they were fleeing fierce fighting in Nasiriyah, further south, when they were hit. He said the strike killed his wife, six children, his father, his mother, his three brothers and their wives.

US Central Command said it was investigating the report but "has not turned up any evidence of this alleged incident."

On Monday, seven people, all women and children, were shot dead when they failed to stop their minibus at a US checkpoint near the holy city of Najaf.

General Richard Myers, chairman of the US joint chiefs of staff, offered his regrets, but added: "The climate established by the Iraqi regime contributed to this incident."

White House spokesman Ari Fleischer said: "Most innocents have been lost in this war at the hands of Saddam Hussein and his henchmen. That's who is to blame for the loss of innocent lives."

The images of carnage played over and over on Arab television stations, and press reports in the United States about internal dissent over how to prosecute the war, have proved a public relations headache for Washington.

The Najaf shooting came after a suicide bomber killed four US troops in the same area on Saturday.

SPACE.WIRE