An explosion killed four people and injured two district officials in northwestern Pakistan on Wednesday, police said according to the AP. Investigators were trying to determine whether a rocket or a remote-controlled bomb killed four passers-by and wounded the police chief of Swat District as well as the district chief, said police officer Akhtar Shah. The explosion occurred outside the police headquarters in the town of Mingora and Shah said the district chief may have been the target of the unknown assailants. Northwest Pakistan, which borders Afghanistan, has been the scene of increasing terrorist activity by radical Muslim groups.
