At least 15 people have been killed and more than 20 injured in two bomb explosions near a police compound in north-western Pakistan. The blasts happened in quick succession in the town of Bannu, south-west of Islamabad. Unconfirmed reports say the blasts were caused by suicide bombers. The first bomb reportedly went off inside the police compound in Bannu. The second blast came as rescuers responded to the first blast. Officials say that most of the victims were police officers. No group has claimed responsibility for the blasts.