The massive manhunt, which continued into Tuesday evening, involved the closure of Hawijah, a town of some 80,000 people, for more than 16 hours, as well as a series of raids on villages around the region, according to Iraqi police who helped lead the US troops to their targets.

Ibrahim's secretary, "Saad Mohammed al-Duri, was arrested in a house in the Hawijah area, where he was hiding," the town's police chief Awad al-Obeidi told AFP.

Forty thousand dollars was found in his possession, which was "suspected of being used to finance attacks on the US-led coalition," said the police chief in the northern oil centre of Kirkuk, 45 kilometres (nearly 30 miles) to the east.

Officers of the US 173rd Airborne Brigade, which carried out the raid on Hawijah, said they had briefly detained a brother or cousin of Ibrahim. It was not immediately clear if he was the same person as Mohammed.

General Turhan Yusef Abdelrahman said more than 100 people were arrested in what he described as a "one-off operation aimed at finding Izzat Ibrahim based on specific intelligence."

Six Iraqis were wounded as several villages put up resistance to the massive cordon and search sweep, he said.

An official of the Patriotic Union of Kurdistan, the dominant Kurdish faction in Kirkuk, said a former general in the disbanded Iraqi army was also arrested in the raids, and an arms cache and attack plans found in his home.

Abrams tanks, Bradley fighting vehicles and Apache helicopters took part in the raid on Hawijah, the biggest conducted in the strongly anti-US town since US troops first rolled through in May.

During the raid, a tank pulled down a mural of Saddam and dragged it into a river.

"We've had a lot of trouble from this town," said Major Andrew Rohling, the 2-503 Battalion's operations officer.

Before dawn, the troops, moving through a cover of dense fog, sealed the area and stormed into the town, where they searched houses suspected of hiding anti-coalition forces.

At one house a terrified boy screamed after a dozen heavily armed soldiers in combat gear burst into his home, handcuffed two men and made the women and children sit on the ground outside in near-freezing temperatures.

"A lot of this is a show of force," Rohling said of the operation.

Hawijah residents "need to be slapped down a little. They are getting too big for their breeches."

By the side of the road, the captured Iraqis were assembled. There, they sat or squatted, shivering. Yellow bags were placed on their heads, with their names marked on them.