An attack on an ambulance in a Pakistani tribal region today killed at least six people, a government official said.
The ambulance was taking people to a health meeting when it was attacked with a rocket-propelled grenade in the Kurram tribal region on the Afghan border.
Pakistan has suffered months of violence, including a campaign of suicide bombing from Islamist militants, that has killed nearly 600 people since the start of the year.
Kurram also has a long history of violence between Sunni and Shia Muslim tribes. Forty people were killed in sectarian violence in December.
Elsewhere, police said they had arrested four men suspected of planning suicide attacks in the eastern city of Lahore. At least 30 people were killed in three suicide attacks in Lahore, the capital of the province of Punjab, this month.