The New Nation - Internet Edition

Reuters, Baghdad

The death toll of U.S. soldiers in Iraq reached 4,000 on Monday, days after the fifth anniversary of a war that President George W. Bush says the United States is on track to win.

The U.S. military said four soldiers were killed on Sunday when a roadside bomb, the biggest killer of American soldiers in Iraq, exploded near their vehicle in southern Baghdad.

One soldier was wounded in the attack, which brought the number of U.S. military deaths to 4,000 since the U.S.-led invasion in 2003.

The deaths came on a day when the U.S.-protected "Green Zone," the government and diplomatic compound in central Baghdad, was hit by repeated rocket and mortar fire, part of an upsurge in violence in the capital and elsewhere.

Sunday's violence, in which dozens were killed, underscored the fragility of Iraq's security. There has been an increase in attacks since January, although U.S. military commanders say overall levels of violence are down 60 percent since last June.

What impact the 4,000 milestone will have on a war-weary American public and the U.S. presidential campaign will be hard to assess in the short term, but war critics are likely to seize on it to boost their case for U.S. troops to be withdrawn.

"You regret every casualty, every loss," U.S. Vice President Dick Cheney said during a visit to Jerusalem. "It may have a psychological effect on the public, but it's a tragedy that we live in a kind of world where that happens."

The U.S. military dismisses such tolls as arbitrary markers.

"No casualty is more or less significant than another; each soldier, marine, airman and sailor is equally precious and their loss equally tragic," U.S. military spokesman Rear Admiral Greg Smith said on Monday.

Anthony Cordesman, a respected Iraq analyst at the Center for Strategic and International Studies in Washington, said the 4,000th death could trigger another wave of polarized debate.

AFP adds: A wave of attacks across Iraq on Sunday killed 54 people, while insurgents bombarded Baghdad's heavily fortified Green Zone with mortar fire, sending US embassy staff scurrying into bunkers.

The deadliest attack was in the main northern city of Mosul where a suicide bomber crashed an explosives-laden truck into an Iraqi army base, triggering a blast that killed at least 12 soldiers and wounded dozens.

"The bomber smashed the truck through barriers at the entrance to the base and triggered the explosion" at around 7:00 am (0400 GMT), army officer Major Mohammed Ahmed told AFP.

The US military in a statement blamed the attack on Al-Qaeda and put the toll at 12 soldiers killed and 35 wounded.

Iraqi and US troops are engaged in a major offensive against Al-Qaeda in Mosul, which according to US commanders is the jihadists' last urban stronghold in Iraq.