A bomb blast at a religious seminary in the Pakistani city of Peshawar on Tuesday killed at least seven people, including children, and wounded dozens, police and hospital officials said.
"Unknown people planted explosives in a plastic bag," said a police officer in the northwestern city who declined to be identified as he is not authorized to speak to media.
Peshawar, near the border with Afghanistan, has long been plagued by Islamist violence.
Though the number of incidents in the city, and in Pakistan in general, had fallen over recent years, there has been an increase this year in attacks on the security forces in Khyber Pakhtunkhwa province, of which Peshawar is capital.
Some of the attacks have been claimed by the Pakistani Taliban.