At least 13 people were killed when a bus carrying Shia pilgrims returning from Iran was targeted with a bomb in Pakistan's restive Balochistan province on Tuesday.
The blast occurred in Dareen Garh area of Mastung district. It was followed by firing, officials said.
"We have confirmed the death of 13 people and 17 others were injured," Frontier Corps spokesman Khan Wasseh said.
Security forces cordoned off the area and the injured were taken to a nearby hospital.
The nature of the blast was yet to be ascertained, Wasseh said.
Local media reports said at least 22 people were killed though this could not be verified independently.
No group claimed responsibility for the attack.
Buses carrying Shia pilgrims have been repeatedly targeted in desolate areas of Balochistan in recent years. Dozens have died in these attacks.