Iraq closes Syria border

Keen to show off the muscle of their US-trained forces, ministers said other towns were in the line of fire and state television ran repetitive footage from recent days in Tal Afar of Iraqi soldiers hunting and detaining men described as rebels.

Residents reported US air strikes overnight, gunfire and an encirclement of US armour in parts of the town as Prime Minister Ibrahim Jaafari announced an offensive had begun.

"At 2 a.m. today (2200 GMT), acting on my orders, Iraqi forces commenced an operation to remove all remaining terrorist elements from the city of Tal Afar," he said in a statement.

Later in the day, a dust storm hindered the offensive, US officers in Tal Afar said. State television ran fresh footage, however, of more arrests and soldiers moving through a town that US troops have seized in the past before withdrawing again.

Jaafari said the troops were responding to appeals for help from "all the different religious and ethnic elements in Tal Afar." The town, west of the northern city of Mosul and near the Syrian border, is mostly populated by ethnic Turkmen.

Civilians had been taken out of the town in recent days as military operations were stepped up, officials said.

US and Iraqi forces have long said Tal Afar was being used as a conduit for equipment and foreign Sunni Arab fighters smuggled in from Syria to fight the Shia and Kurdish-led Iraqi government and occupying US forces across the country.