The US military has launched an investigation into claims that American forces shot dead 15 members of two families, including a three year-old-girl, shortly after a roadside bomb killed a US Marine in a western Iraqi town.

In a rare statement against violence, al-Qaida in Iraq purportedly issued a statement today denying it was behind a horrific attack on a poor east Baghdad neighbourhood that killed 18 children and teenagers.

At least two people died in a suicide car bombing explosion in Iraq today, with 10 people injured, including four US soldiers, according to Iraqi and coalition officials.

LEADING allies of the United States sought yesterday to defend the legal basis for their support of the US-led invasion of Iraq after UN chief Kofi Annan said it was illegal.

Militants pounded central Baghdad today with one of their most intense mortar barrages ever, targeting the Green Zone and destroying a US vehicle along a major street.