An explosion took place at Haji Bakhshi mosque in Qala-e Murad Bek area of Shakardara district, north of Afghan capital, Kabul, provincial police said.
According to a police spokesman, Ferdaws Faramarz, the blast took place around 1:30pm during Friday prayer, killing and wounding dozens.
Initial reports indicated four people were killed and more than 20 wounded in the explosion.
The police spokesman then put the toll to 12 killed and more than 15 wounded.
Imam of the mosque was also among the dead, according to him.
There was no claim of responsibility for the attack and the Taliban denied to be involved.
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