Thirteen people were killed and 10 wounded in a bomb attack on an air force bus in the northwestern Pakistani city of Peshawar on Tuesday night.
There had been no claim of responsibility, but Islamic militants based on the Afghan border have been blamed for a series of attacks on security forces during the past year.
The attack followed days of fighting, including air strikes, between militants and security forces in the Bajaur region, a militant hot spot north of Peshawar.
About 150 militants, including a senior al Qaeda member, have been killed.
