ISLAMABAD - Gunmen attacked a Pakistani Air Force base in the northwestern city of Peshawar early on Friday, a military spokesman said, the first major attack in several weeks. A group of between seven and 10 militants attacked a guard post and tried to force their way into the Badaber air base, Major General Asim Bajwa said on Twitter. A gunbattle was still underway and three attackers had been killed so far, he said. 'Terrorists engaged, contained around guardroom area,' Bajwa tweeted.