The Iraqi city of Fallujah was braced for its third military assault in less than a decade, after government forces surrounded it with heavy armour in an attempt to dislodge al-Qaeda fighters.
Tanks and artillery units sealed the city and civilians were ordered to leave, setting the stage for what residents fear could be a prolonged bout of urban combat.
The battle is a test of the Government's authority, but doubts are growing about the ability of Iraqi forces to dislodge the well-armed extremists, who also seized the nearby city of Ramadi last week.
A similar operation in Ramadi overnight ended in failure, with jihadis from the Islamic State of Iraq and Syria still dug in around several districts of the city, despite a Government missile strike that killed 25 people. Residents of Fallujah fear the Iraqi Army will resort to overwhelming power with rockets and tank fire. "If the army attacks Fallujah to fight a handful of al-Qaeda elements, that will have dire consequences by triggering endless violence," one tribal leader in Fallujah said.
But Nouri al-Maliki, Iraq's Prime Minister, appears to be running out of confidence in the ability of tribal leaders to act as policemen.
