A suicide bomber killed 25 people when he blew himself up inside a packed Shi'ite Muslim mosque in Kuwait city during Friday prayers, the first attack of its kind in the major oil-exporting country.
The Islamic State militant group claimed responsibility for the attack, which also wounded 202 people, in the district of Sawaber in the eastern part of the Kuwaiti capital.
Parliament member Khalil al-Salih, who was at the mosque when the attack occurred, said worshippers were kneeling in prayer when the bomber walked into the Imam al-Sadeq Mosque and detonated his explosives, destroying walls and the ceiling.
"It was obvious from the suicide bomber's body that he was young. He walked into the prayer hall during sujood (kneeling in prayer).
"He looked ... in his 20s, I saw him with my own eyes. The explosion was really hard. The ceiling and wall got destroyed," he said, adding that more than 2,000 people from the Shi'ite Ja'afari sect were praying at the mosque.
Security forces quickly sealed off the perimeter of the mosque while rescue workers carried the wounded to hospital.
Islamic State named the bomber as Abu Suleiman al-Muwahed and said in a statement posted on social media that he had targeted a "temple of the rejectionists" - a term it generally uses to refer to Shi'ites, whom it regards as heretics.
Islamic State had urged its followers on Tuesday to step up attacks during the Ramadan fasting month against Christians, Shi'ites and Sunni Muslims fighting with a US-led coalition against the ultra-hardline jihadist group.
The Health Ministry said Kuwait's blood bank had opened additional centres to receive blood donations and it urged citizens with non-urgent medical needs to avoid the emergency units.
Pictures posted on social media and Kuwaiti news websites showed men in traditional white robes smeared with blood outside the mosque.
A second photo showed a row of victims wrapped in white body bags and a third the collapsed ceiling of the mosque.
Prime Minister Sheikh Jaber al-Mubarak al-Sabah condemned the bombing as an attempt to jeopardise Kuwait's national unity.
"This incident targets our internal front, our national unity. But this is too difficult for them and we are much stronger than that."