US soldiers' death toll in Iraq exceeds 4,000

Just days after the fifth anniversary of the start of the Iraq war, the US military has said the death toll among US soldiers killed in the conflict now exceeds 4,000. It follows the killing of four soldiers late on Sunday when a roadside bomb exploded near their vehicle in southern Baghdad. The deaths come as the Iraqi capital experiences an upsurge of violence in which dozens were killed at the weekend.

Michael O'Hanlon from the independent research and policy Brookings Institute said:

"I frankly think we are saddened by each loss of life and we have had multiple milestones before and therefore I think we have to keep this in perspective. It is not going to be seen as a major symbolic plateau or threshold or new milestone. It is just going to be another reminder of the grim toll of war."

The conflict remains a major issue in the ongoing presidential campaign, with supporters and opponents waging a war of words on the streets.

President Bush insists the US is on track for victory, arguing that any troop withdrawal would embolden the enemy.

On the Iraqi side, the exact number of casualties remains a mystery with the most conservative estimates standing at around 80,000. Others believe the real figure could be ten times that figure.