Saudi Arabia said Saturday that the suicide bomber who detonated an explosives-packed vest in a mosque inside a police headquarters, killing 15 people, was one of its own citizens.

Saudi Arabia said Saturday that the suicide bomber who detonated an explosives-packed vest in a mosque inside a police headquarters, killing 15 people, was one of its own citizens.

Thursday's bombing of a mosque frequented by members of a police special weapons and tactics unit in the southern city of Abha was claimed by the ISIL group.

The Saudi interior ministry named the bomber as Yussef bin Sleiman bin Abdullah al-Sleiman, aged 21.

A ministry spokesman, quoted by El-Ekhbariya state television, said 11 of those killed were policemen and four were Bangladeshis who worked at the police compound.

ISIL affiliate "Al-Hijaz Province" said in an online statement that it was behind the attack, the latest -- and deadliest -- against security forces in Saudi Arabia in recent weeks.

It had identified the bomber as Abu Sinan al-Najdi and vowed to carry out fresh strikes against "tyrants in the Arabian Peninsula... in the coming days".

There was no explanation as to why different names were given, but the one published by ISIL appeared to be an alias.