At least 14 people, mostly schoolgirls, have been injured after a bomb exploded in Quetta in the south-west Pakistani province of Balochistan.
The bomb is said to have been planted in front of a grocery store. A girl's college is located nearby.
The big explosion damaged several nearby shops. But none of the injuries are said to be serious, according to doctors at a local hospital.
Balochistan has witnessed steady violence in recent months.
It is not clear who was behind the latest attack.
"It was a homemade bomb but we don't know who had planted it and what was the motive," local police chief, Wazir Nasir, is quoted as saying by the Associated Press news agency.
The bomb went off as the girls were on their way home from the college.
Last week, some 28 people belonging to a wedding party died when their vehicle hit a landmine in Balochistan's Dera Bugti district.
Police alleged that tribal rebels had planted the landmine.
Gas-rich Balochistan has seen months of violence as tribal groups push for greater political and economic rights.
Tribal separatists have attacked gas plants, electricity lines and railway tracks.
Government forces launched military operations in Kohlu and Dera Bugti districts in December after rockets were fired near President Musharraf when he visited the province.
According to local tribal leaders, a large number of civilians have died in the military operation, but this has not been confirmed by officials.