THE massive blast when a petrol tanker exploded in a fireball after colliding with a bus in the centre of Baghdad yesterday, killing 17 Iraqis, was an accident, said US military investigators.

Saddam Hussein loyalists rioted in Baghdad, ambushed a US patrol in Samarra, stormed the office of a US-backed mayor in Fallujah and battled American troops in Ramadi as cities in Iraq’s “Sunni Triangle” region seethed over the ex-dictator’s capture.