Pakistan is to step up its offensive against the Taliban after suspected militants attacked the army’s headquarters in Rawalpindi.Commandos stormed a security office building, rescuing 39 people kidnapped after Saturday’s brazen asault. Three hostages, two soldiers and four of the gunmen were killed in the operation, while another was captured. Yesterday gunmen wearing army uniforms drove up to the heavily guarded complex and opened fire, killing six soldiers, including a brigadier and a lieutenant colonel, in a gun battle at the main gate. Five gunmen were killed there and two of their wounded colleagues captured. But others fled and took hostages in a building housing offices near the headquarters. It has been a bloody week for Pakistan. Suicide bomb attacks in Islamabad and Peshawar have left more than 50 people dead. This latest attack bore similarities to several audacious strikes against high profile security targets this year, calling into question government assertions the militants have been virtually crippled by recent setbacks.