A search is underway for two gunmen involved in a deadly attack on Pakistan’s army headquarters close to the capital, Islamabad.The suspected militants, dressed in combat fatigues, are said to have driven up to the gate of the heavily guarded complex and opened fire. A lengthy gunbattle followed during which four of the assailants were killed. Six soldiers are now known to have died. According to one report, two other soldiers have been taken hostage from the compound at Rawalpindi. The attack comes as the army prepares for a major offensive against Pakistani Taliban and al-Qaeda militants in their northwestern stronghold on the Afghan border. It also follows Friday’s suspected suicide car-bombing which killed 49 people in the northern city of Peshawar.