A roadside car bomb has hit a bus of Shiite pilgrims returning to Pakistan from Iran, killing 20 people and wounding more than 30 in restive Baluchistan province.
Security officials said women, children and four paramilitary troops were among those killed. The troops were escorting the Shiite convoy. More women and children were wounded by the blast and subsequent fire.
Police said the bomber detonated explosives planted in a car along the road when a convoy of buses passed by in the Dren Garh area of Mastung district, 36 miles west of Quetta, the capital of Baluchistan province.
Blame is likely to fall on Islamist militants, some of whom consider Shiites heretics and have claimed attacks on the sect in the past. Ethnic nationalist insurgents also operate in Baluchistan.