Taliban militants have seized control of a district in Afghanistan's volatile south after an hours-long clash that killed five people, including the local police chief and the political leader, a deputy governor said Friday. The Taliban launched the attack Thursday evening on the Giro district of Ghazni province, setting fire to several buildings and cutting communication lines, said provincial deputy governor Kazim Allayer. The district chief and four policemen, including the police chief, were killed in a battle with the militants that lasted several hours, Allayer said. Police reinforcements have been sent to the area, Deputy police chief Mohammad Zaman said. "Giro collapsed last night, captured by the Taliban after heavy fighting between the police and the Taliban," said Gen. Murad Ali, deputy regional corps commander of the Afghan army. Ali said that early Friday the Afghan army sent troops from Ghazni and Paktika to assist. NATO and the US-led coalition said they were aware of the incident. "The details are very sketchy right now. We're tracking it closely," said Maj. William Mitchell, a spokesman for the US-led coalition. After a winter lull in attacks, the Taliban have stepped up bombings and attacks in recent weeks, as NATO-led forces push forward with their biggest ever offensive in southern Afghanistan to root out militants in the opium-producing heartland of Helmand province. Meanwhile in eastern Khost province, gunmen assassinated a criminal investigation policeman as he was driving Friday in Tani district, said provincial police chief Gen. Mohammad Ayub. A relative in the car was also killed, and the driver was wounded, Ayub said, adding that two suspects have been arrested. It was not immediately clear if it was a personal conflict or an insurgency attack. In southern Uruzgan, Taliban militants ambushed a police convoy patrolling late Wednesday night, and the ensuing clash left four policemen and six Taliban dead, said provincial police chief Gen. Abdul Qasim Khan.