A bomb attack on a mosque in Pakistan has killed at least 13 people, including a senior police officer.
The explosion happened on Friday in the city of Quetta in south western Pakistan, police have confirmed.
At least 20 worshippers were injured in the blast, many of whom are in a serious condition.
Local police chief Mohammad Ajmal said the slain police officer was the likely target of the attack, but authorities were still investigating.
Police said an improvised explosive device had been planted in the mosque inside a seminary.
"So far, 13 bodies and 20 injured have been brought here," Dr Wasim Baig, spokesman for a local hospital told Reuters, adding that many of the injured were in serious condition.
The death toll from the bombing is likely to rise, authorities have said.
No one immediately claimed responsibility for the bombing. But the attack came just days after a roadside bomb in Quetta hit a paramilitary force vehicle, killing two troops.
Hizbul Ahrar, an offshoot of the Pakistani Taliban, claimed responsibility for Tuesday's attack.
Last May, a bombing at a mosque in Quetta killed two people, including the prayer leader, and wounded 28 worshipers. In August, a powerful bomb exploded inside a mosque during Friday prayers on Quena's outskirts.
Although Pakistani militants often carry out such attacks, Baluchistan province is also the scene of a low-level insurgency by separatists demanding more autonomy and a greater share in the region's natural resources such as gas and oil.
The Afghan Taliban have had a strong presence in Quetta. The province shares a long border with Afghanistan and Iran.
Pakistan's government claims it has quelled the insurgency, but violence has continued.
