Police raided a suspected militant hide-out in northwestern Pakistan early Saturday, triggering a shootout that killed at least two officers and wounded two others, police said. The gunbattle occurred in Mardan town, about 50 kilometers (30 miles) northeast of Peshawar, the capital of North West Frontier Province, when officers surrounded a house and asked the occupants to surrender, said Abdul Qayyum, a local police official. "The militants are using assault rifles. They have killed two of our officers, and so far we do not know whether they have suffered any casualties," he said. The firefight was the latest in a series of increasingly bloody clashes between pro-Taliban militants and security forces in areas near the Afghan border. In recent months fighting has spread to other parts of Pakistan, including major urban centers such as the port city of Karachi.