Kuwait on Sunday identified a suicide bomber who carried out the country's worst militant attack as a Saudi citizen and said it had detained the driver of the vehicle that took him to a Shi'ite mosque where he killed 27 people.

The interior ministry named the bomber as Fahd Suliman Abdul-Muhsen Al Qabaa and said he flew into Kuwait's airport at dawn on Friday, only hours before he detonated explosives at Kuwait City's Imam al-Sadeq mosque.

Militant group Islamic State claimed responsibility for the suicide bombing at the mosque, where 2,000 worshippers were praying at the time. It was one of three attacks on three continents that day apparently linked to hardline Islamists.

"The interior ministry will continue its efforts to uncover the circumstances of this explosion," interior ministry spokesman Adel Hashash told Kuwait state television.

The bombing has sharply heightened regional security concerns because Islamic State appears to be making good on its threat to step up attacks in Ramadan.

The ministry said the driver of the Japanese-made car, who left the mosque immediately after Friday's bombing, was an illegal resident named Abdul-Rahman Sabah Aidan.

The interior ministry, which had earlier reported the vehicle owner's arrest, said Aidan, 26, was found hiding in one of the houses in al-Riqqa residential area.

"Initial investigations showed that the owner of the house is a supporter of the deviant ideology," the ministry said, employing a term often used by authorities in the Gulf region to refer to hardline Islamist militants.

The owner of the house, a Kuwaiti citizen, was also detained, the ministry said.

Officials said the bombing was clearly meant to stir enmity between majority Sunnis and minority Shi'ites and harm the comparatively harmonious ties between the sects in Kuwait.

Shi'ites are between 15 and 30 per cent of the population of Kuwait, a mostly Sunni country where members of both communities live side by side with little apparent friction.-Reuters