Authorities have also detained the owner of the house used as a hideout by the bomber, a Kuwaiti national who subscribes to “extremist and deviant ideology,” the ministry said in a statement.

The suicide attack, the first bombing of a mosque in the oil-rich Gulf state, was claimed by the Daesh (Arabic acronym for the group calling itself Islamic State) jihadist group.

The Daesh-affiliated group in Saudi Arabia, calling itself Najd Province, said militant Abu Suleiman Al-Muwahhid carried out the bombing.

The driver, named Abdulrahman Sabah Eidan Saud, was described as an “illegal resident” born in 1989, who took the bomber to the Al-Imam Al-Sadeq mosque in Kuwait City on Friday.

“Illegal resident” is the official term used in Kuwait to describe stateless people, locally known as bidoons, who number around 110,000 and claim the right to Kuwaiti citizenship.

The driver had been hiding in a house in the Al-Rigga area in the city’s southern Al-Ahmadi Governorate.

Authorities on Saturday arrested the owner of the car, Jarrah Nimr Mejbil Ghazi, born 1988, and also listed as a stateless person.

Although Daesh named the perpetrator, authorities have so far been unable to identify him from remains found at the scene, Al-Anbaa daily reported.

Samples of the body were sent to neighboring countries for DNA tests as no records of his were found in Kuwait, the daily said.

Authorities will “continue efforts to uncover the conspirators in this criminal act and to reveal all of the information and circumstances behind it,” the interior ministry said.

The attack is the first claimed by Daesh jihadists in the small Gulf emirate.

Local media said 18 of those killed were Kuwaitis, three Iranians, two Indians, one each from Pakistan and Saudi Arabia and one bidoon.