By RIAZ KHAN and MUNIR AHMED
PESHAWAR, Pakistan (AP) — Pakistani authorities are scrambling to determine how a suicide bomber was able to carry out one of the country’s deadliest militant attacks in years. The attacker unleashed an explosion in a crowded mosque inside a highly secured police compound in the city of Peshawar. The death toll from the blast climbed to 100. Monday’s bombing, which left at least 225 wounded, raised alarm among officials over a major security breach. The defense minister accused the Pakistani Taliban, the main anti-government militant group which has stepped up attacks, of being behind the bombing, using Afghan territory as a base.