A number of people were reportedly killed and injured on June 26 in an explosion at a Shi'ite mosque in Kuwait City as Friday prayers were being held while worshippers gathered during the holy month of Ramadan.
The attack was claimed by the Islamic State group.
Kuwaiti officials said a suicide bomber triggered the explosion.
Medics said at least 13 people were killed in the explosion. The official KUNA news agency confirmed that there were "dead and wounded," but did not provide details.
The Gulf nation, which has a mixed population of Sunni and Shi'ite Muslims, has enjoyed relative security and stability, despite often turbulent parliamentary politics.