An explosion rocked a mosque in central Kabul during prayer time on Wednesday, injuring at least six people, officials said.
The blast was the second in a week in the Afghan capital, after another tore through the main money exchange centre, killing one person and injuring dozens.
Wednesday's explosion occurred after someone threw a grenade at the mosque, and one person had been arrested, according to a spokesman for Kabul's military commander.
The attacks have hit the capital after a relative lull in violence over the cold winter months.
The ruling Taliban say they have secured the country since taking over in August and most fighting has ended. But international officials and analysts say that the risk of a resurgence in militancy remains and the Islamic State jihadist group has claimed several major attacks.