A suspected suicide car bomb ripped through a police building in an army garrison of Pakistan's northwest city of Peshawar on Friday, killing up to 11 people, police said. It was the second bomb attack in Peshawar in 24 hours, striking a day after 40 people died in a wave of militant attacks against security targets in Pakistan's eastern city Lahore and the country's volatile northwest. "I have counted 11 dead bodies and 13 wounded in the emergency unit of the hospital," police official Mohammad Gul told media by telephone from the main government-run hospital in Peshawar. Ambulances screeched through the streets, sirens blaring as rescue teams rushed to the scene of the attack, where TV footage showed smouldering wreckage and a damaged brick wall. Police at the scene earlier put the death toll at seven with detainees in custody at the police building among the wounded. "There are seven killed and 15 wounded in a car bomb blast. There are some prisoners among the injured," said senior police official Mohammad Karim Khan. North West Frontier Province police chief Malik Navid told Pakistan's state PTV it was an apparent suicide attack, with the bomber driving a car. The bomb ripped through the police-run Central Investigation Agency (CIA) building in Peshawar -- the largest city in northwest Pakistan which lies on the fringes of the lawless tribal belt on the Afghan border.