A bomb exploded in a mosque in eastern Afghanistan during Friday prayers, officials said, killing at least 29 men who had gathered for worship.
Sohrab Qaderi, a member of the provincial council in Nangarhar, said at least 29 people had been killed and more than 100 others wounded.
"The number of casualties may rise as the rescue team and people are working to bring out the bodies from the rubble," Qaderi added.
Attaullah Khogyani, the spokesman for Nangarhar's provincial governor, said the roof of the mosque had fallen in due to the blast and so far more than 20 were reported dead.
No militant group has claimed responsibility so far.