An official says three grenades were thrown into a mosque compound during morning prayers in eastern Afghanistan, wounding at least nine worshippers.
Wednesday's attack in Khost province comes a day after a series of bombs across Afghanistan killed 46 people. It was the deadliest day for civilians this year.
The Khost police chief says one of the grenades exploded inside the mosque itself in Baghi Sara area. Two others landed in the courtyard outside and one of those failed to detonate. The police chief blames Taliban insurgents.
A Taliban spokesman issued a statement saying the insurgents had attacked a U.S. base in Khost with a suicide bomber but did not acknowledge the mosque attack.
The NATO military coalition had no immediate comment.