SURRENDER talks were taking place between Iraqi officials and allied commanders early today as one of history's most ferocious aerial bombardments rained down on Baghdad.

While the promised "shock and awe" onslaught through the night, speculation was also mounting that Saddam Hussein may have been killed or injured in an earlier bombing raid.

There were further signs that Iraq's resistance was crumbling when it was announced that Saddam's 8,000-strong 51st Division had surrendered to US marines at Basra.

But in an alarming escalation of the conflict, Turkey last night moved 1,000 troops into northern Iraq after giving US warplanes the right to use its airspace.

A further 5,000 soldiers are being sent to the border region, said a military official in Ankara.

Foreign Minister Abdullah Gul said Turkey was determined to contain a possible refugee flow and prevent any attempt by Iraqi Kurds to break away from Iraq.

The action came despite strong opposition in Washington to any unilateral move by Turkey into northern Iraq.

Earlier, in chilling scenes witnessed live by millions of TV viewers around the world, cruise missiles and air-launched guided bombs pounded targets in Baghdad and across the country.

The assault was unprecedented in its firepower with 2,000 sorties by coalition aircrews, firing 1,000 cruise missiles at 1,500 targets - three times more than in Desert Storm in 1991.

Fires raged across the Iraqi capital, with Saddam's "Old Palace" compound, the main seat of government, among the targets reported to have been hit at the start of "A Day" - the beginning of the air war. Cities in the north of Iraq - Mosul, Tikrit and Kirkuk - was also hit.

The chairman of the US Joint Chiefs of Staff General Richard Myers told a Pentagon news conference that "several hundred targets" would be attacked during the course of the night.

British Tornado GR4s and GR3s and Harrier GR7s were among the strike force.

Tomahawk cruise missiles were launched from British submarines HMS Splendid and HMS Turbulent as well as US aircraft and warships.

The onslaught came at the end of a day of rapid advances by British and US ground forces which took them to the gates of Iraq's second city, Basra.

US Defence Secretary Donald Rumsfeld said that the air attacks would be of a "scope and scale" which made it clear to Iraqis that Saddam and his regime were finished.

"The regime is starting to lose control of the country," he said.

"They are beginning to realise, I suspect, that the regime is history and as that realisation sets in their behaviour is likely to begin to tip and to change.

"Those close to Saddam Hussein will likely begin searching for a way to save themselves."

Mr Rumsfeld said all the strikes were precisely targeted at military objectives and at the apparatus of the Iraqi regime.

The vast array of airpower at the disposal of coalition commanders included eight American B-52 bombers which were returning from Baghdad to RAF Fairford in Gloucestershire, at 2am this morning.

Iraqi troops were reported to be surrendering across the country in "significant numbers" as US and British armoured columns punched deep into Iraq.

The Chief of Defence Staff Admiral Sir Michael Boyce said that the prisoners of war could number "several hundreds".

The US 3rd Infantry Division was said to have advanced about 100 miles into Iraq towards Baghdad, prompting one military official to predict that they could be in the Iraqi capital in three or four days.

At the same time, US forces supported by two battlegroups of the British 7th Armoured Brigade - the Black Watch and the 1st Battalion, the Royal Regiment of Fusiliers - advanced into the outskirts of Basra. Early today, there were reports the city was about to fall.

Royal Marine commandos, who staged an amphibious and airborne landing on Thursday night on the Al Faw peninsula, yesterday secured the area's oilfields.

Sir Michael said: "Our marines took their objectives despite sporadic fighting which also included some stern resistance.

"There were some enemy casualties including some enemy dead."

Meanwhile, British Army specialist units, including the Royal Engineers, bomb clearance teams and nuclear, biological and chemical units, were helping American troops to secure the southern oilfields.

Sir Michael told a Press conference that only seven oil wells had so far been set alight by the Iraqis.

Coalition commanders had originally feared that as many as 30 wells had been torched, but Sir Michael said that they had mistaken smoke palls from trenches filled with burning oil.

RAF Tornados spearheaded the bombardment of Baghdad, targeting radar defence systems protecting Saddam's high command.

Other successes for the coalition included the capture by US marines of the key southern port of Umm Qasr, which will become the main gateway for humanitarian aid to flow into the country once Royal Navy minesweepers have cleared the waters of mines.

The Stars and Stripes flag was briefly raised over the city but was quickly removed. Coalition commanders are anxious that they should be seen as an "army of liberation" rather than an occupying force.

Sir Michael expressed satisfaction at the way the campaign was progressing.

"It is very early days, but I have to say the coalition progress so far has been promising," he said. "I am very encouraged by the start we have made."

The day, however, brought the confirmation of the first coalition casualties. Eight Royal Marines and four US aircrew were killed when a US Sea Knight helicopter crashed in the Kuwaiti desert on Thursday night. Officials said it was not the result of enemy action.

Two US marines were also killed in combat.

Tony Blair paid tribute to the dead. "These were brave men who in order to make us safer and more secure, knew the risks, faced the risks and had the courage to serve their country and the wider world," he said.