PESHAWAR, Pakistan (AP) — At least seven police officers and six militants were killed after gunmen attacked a police training center in northwestern Pakistan , triggering a fierce firefight that lasted for hours, officials said Saturday. It’s the latest violence to rock the area, which is the base for several armed groups, and comes as Pakistan struggles with a worsening security situation . Friday night’s assault targeted a police training facility in Ratta Kulachi, on the outskirts of Dera