US and Iraqi forces fanned out Tuesday in the volatile Diyala province in a new operation aimed at clearing Al-Qaeda in Iraq from safehavens in an area considered the last major insurgent belt around the capital. New checkpoints were erected across the province and authorities ordered a ban on unofficial traffic as search operations got under way in the provincial capital of Baqouba and surrounding areas, according to witnesses. Many residents said they were afraid to leave their houses. The US-backed Iraqi military is hoping to build on recent security gains from similar offensives against Sunni insurgents in the northern city of Mosul and Shiite militiamen in Baghdad and the southern cities of Basra and Amarah. The troops were focusing on chasing Al-Qaeda and other insurgents, who have sought refuge in Diyala to escape earlier crackdowns, said Gen. Ali Ghaidan, the commander of Iraqi ground forces in the province, who announced the start of the operation. Ghaidan said the operation's goal is “to clear Diyala from Al-Qaeda.” “We have a list of wanted persons that the troops will arrest during the operation,” Ghaidan said. The province, which sits to the north of the capital and borders Iran, has been one of the hardest areas to control since the US-led war began in March 2003. Baqouba, the provincial capital, was hit by twin suicide bombings that killed at least 28 people on July 15 and has seen a number of female suicide attacks. “The goal of the operation is to seek out and destroy criminal elements and terrorist threats in Diyala and eliminate smuggling corridors in the surrounding area,” the US military said in a statement. The military said it was an Iraqi-led operation, stressing the point as the Iraqi government is seeking to assert more control over military operations. “We applaud the Iraqis' growing ability to lead, plan and execute complex combat, policy and humanitarian operations and we look forward to reducing our support footprint as security conditions on the ground permit,” the statement said. The religiously mixed area is strategic because it contains key supply routes to Baghdad and northern cities that need to be controlled to ensure the areas' security. Similar offensives against Shiite militiamen in Baghdad and southern cities have contributed to a sharp decline in attacks. But violence has been slower to decline in Diyala and elsewhere in northern Iraq despite several military operations in recent years. Major Gen. Mark Hertling, who commands US forces in northern Iraq, has expressed confidence that this effort will be more successful because Iraqi security forces are better prepared.