Pakistani authorities say a bomb blast at a Shi'ite mosque in the North West Frontier Province has killed four people and wounded at least three others.
Police say the bomb went off Monday as worshipers were leaving the mosque in Dera Ismail Khan after evening prayers.
The bomb destroyed the mosque's front wall and damaged its dome. Police cordoned off the area as people searched the rubble for survivors.
No one has claimed responsibility for the attack.
Dera Ismail Khan has a history of sectarian violence.
Last month, gunmen killed at least six Shi'ite Muslims in two suspected sectarian attacks in the city.
Pakistan has a history of violence between the majority Sunni and minority Shi'ite Muslims. The communities generally coexist peacefully, but militants from both sides have attacked each other since the 1980s, killing thousands of people.
Some information for this report was provided by AFP, AP and Reuters.