More than 30 large explosions struck the southern outskirts of the Iraqi capital Baghdad as dawn broke on Wednesday and another hit the city centre, a reliable source said.

"They are really pounding the area," said the source, adding that buildings in the city centre were shaking.
President Saddam Hussein's trusted Republican Guards are believed to be dug in on the southern flank of the city to defend it against invading US and British forces.
No anti-aircraft fire could be seen and air raid sirens remained silent in this city of over five million people.
Smoke could be seen rising from an area of Baghdad where the ministry of information and television station are situated.
On Wednesday morning, Iraq's satellite television was showing either a blank screen or sporadic still pictures which suggested technicians were struggling to bring it back.
Iraq's domestic television normally does not start broadcasting until later in the day.
Late on Tuesday night several large explosions were heard in the city centre and televisions in one hotel where journalists were staying immediately went black. The television resumed broadcasting later.
An official at Iraq's television station blamed a "technical problem in the transmitters" for that blackout.
{{/usCountry}}An official at Iraq's television station blamed a "technical problem in the transmitters" for that blackout.
{{/usCountry}}The dawn raids on Wednesday came as a sandstorm that has enveloped Baghdad and hampered visibility eased. The sky was cloudy but visibility quite good.
ALLIES CLAIM PROGRESS
On the sixth day of the US-led war to topple Iraqi President Saddam Hussein, the allied forces reported gains in the south, seizing the key, but small, port of Umm Qasr on the border with Kuwait and crossing the Euphrates river at the town of Nasiriyah to press northwards.
In a multi-pronged offensive, the US Army's Third Infantry Division was closing in on Baghdad, field reports said. The 101st Airborne Division was moving up from the southwest.
But their advance through the desert could be slowed by howling winds and swirling sand, which elsewhere in southern Iraq have grounded helicopters and brought tanks and amphibious vehicles to a standstill.
The unexpectedly tough resistance met in the desert towns which US war planners had thought would be a walkover for US troops, has raised fears for what the coalition forces could meet in Baghdad.
'TOUGHEST FIGHT AHEAD'
"The toughest fight is ahead of us," General Richard Myers, chairman of the US Joint Chiefs of Staff, told ABC television. "We know it will be a very tough battle.
"We also anticipate that (in) this next phase, as we get closer to Baghdad, that the resistance will get tougher," he said, adding the Republican Guard were "best trained, best equipped and reportedly the most loyal to the regime."
Casualty tolls remain unreliable, with the Iraqis saying 30 have been killed and more than 400 wounded in the bombings of Baghdad, while the American and British troops have sustained an undetermined number of losses.
But Meyers added Operation Iraqi Freedom was going pretty much to plan, even though Saddam has remained defiant and has predicted that Iraq would win the war.
Iraqi officials have hinted they could try to draw US and British forces into dangerous street battles risking high civilian and military casualties -- under the glare of the world's cameras with hundreds of "embedded" journalists riding pillion with the troops.
Already US and British officials have been surprised at the determined fight put up in both Umm Qasr and Nasiriyah.
In Nasiriyah it was the same picture, as a column of about 4,000 US marines ran the gauntlet of heavy Iraqi fire to cross the Euphrates River in the city located about a third of the way north from Kuwait to Baghdad.
OBSTACLE DUST STORM
As a howling dust storm cut visibility to 25 meters, about 500 marines and some 50 tanks and armored vehicles held the two kilometers (1.2 miles) of dangerous ground between the bridges.
"It was about as dangerous as it comes," said Commander Ken Kelly.
The battle of Nasiriyah was the first trial for the US-British forces of the nasty urban warfare which they had vowed to avoid.
More than 100 Iraqi bodies were left littering the road north from Nasiriyah after the six-day standoff and the odour of burnt flesh filled the air.
BLAIR HEADED FOR AMERICA
British Prime Minister Tony Blair, announcing he was to go to Washington on Wednesday for talks with US President George W Bush, said coalition forces were advancing towards Baghdad in a two-pronged assault.
"Our aim remains as has been stated -- to remove Saddam as the route to disarming Iraq of weapons of mass destruction -- so the progress towards Baghdad is of vital strategic importance."
He said he would also meet with UN Secretary General Kofi Annan.
$74 BILL FOR WAR
Bush was due to head to the Pentagon Tuesday to tout the "steady advance" of US-led forces and unveil a 74.7-billion-dollar emergency spending bill to cover war costs this year.
The bill will include some 63 billion dollars for fighting the war, as well as about eight billion dollars for rebuilding Iraq.
BASRA PRECARIOUS
The situation in Basra remained precarious Tuesday where the Britain's 7th Armoured Brigade or Desert Rats, which is spearheading the drive on the city, were encountering fierce resistance on the outskirts.
Arabic satellite channel Al-Jazeera reported Western warplanes dropped cluster bombs over Basra overnight amid intense ground fighting on its outskirts.