A suicide bomber has killed at least 11 people in northwestern Pakistan, in an attack targeting Shi'ite Muslims.
Police say the bomber detonated his vehicle outside a hospital in Hangu, in Pakistan's Khyber Pakhtunkhwa province.
Reports say the hospital was being built by the area's Shi'ite community. Friday's attack occurred one day after the start of the holy month of Muharram, which is especially important for Shi'ites and is often marred by bombings by Sunni extremists.
In a separate development, a suspected U.S. missile strike killed four alleged militants who were traveling in a vehicle in Pakistan's North Waziristan region. The attack took place about 40 kilometers west of Miranshah, the main town in the region.
U.S. officials do not comment on the strikes, which are directed at militants who use the area as a staging base for attacks in neighboring Afghanistan.
Friday's suicide bombing in Hangu is the fourth such attack this week in Pakistan. It comes just two days after a teenage suicide bomber killed at least 17 people in the nearby town of Kohat.
On Tuesday, a suicide bomber tried to assassinate the chief minister of the southwest province of Baluchistan, wounding at least nine people but not harming the minister.
On Monday two suicide bombers killed 43 people when they attacked a gathering of anti-Taliban militia leaders in Mohmand, in Pakistan's resitive tribal areas.