At least eight people were killed and several others injured when an explosion ripped through a Shia mosque in Kuwait city after Friday prayers, the media reported.
Al Jazeera news network said the explosion shook the al-Sadeq Shia mosque.
Emergency services rushed the wounded to hospitals from the scene, where thick clouds of black smoke were seen.
Many of the wounded were in critical condition, media reports said.
On May 30, four people were killed in Dammam, a city in eastern Saudi Arabia, after a suicide bomber's explosives blew up in the parking lot of a Shia mosque.
The Islamic State group claimed responsibility for that attack.