File image - Pakistani security officials examine the site of bomb blast in Karachi.

Quetta, Pakistan - A car bomb attack on a bus in Pakistan's insurgency-hit southwest killed at least three Shiite pilgrims and wounded 25 more on Sunday, officials said.

The remote-controlled bomb hit a convoy of three buses in Mastung district, some 30 kilometres (18 miles) south of Quetta, the capital of oil and gas rich Baluchistan province, which borders Iran and Afghanistan. - Sapa-AFP