An Islamic State (IS) group suicide bomber has detonated an explosives-packed vest in a mosque inside a Saudi special forces headquarters killing 15 people.
In the latest in a string of IS attacks in the kingdom, the interior ministry on Thursday (local time) said the bomber struck during noon prayers in the city of Abha, in the southern province of Asir near the border with war-strewn Yemen.
Twelve of those killed were members of a Special Weapons and Tactics (SWAT) unit, while the other three were workers at the compound, officials said. Seven other people were wounded.
"The terrorist attack struck worshippers during prayer," the spokesman said, giving an initial toll of 10 policemen and three workers killed and nine people wounded.
El-Ikhbariya state television later said that two policemen wounded in the "heinous" attack had died, bringing the death toll to 15.
IS affiliate "Al-Hijaz Province" said in an online statement that it was behind the attack, the latest - and deadliest - against security forces in Sunni-ruled Saudi Arabia in recent weeks.
The statement identified the bomber as Abu Sinan al-Najdi and said the jihadist infiltrated the special forces headquarters in Abha and activated his explosives vest, killing and wounding dozens.
Al-Hijaz Province vowed to carry out fresh strikes against "tyrants in the Arabian peninsula... in the coming days".
Another IS-affiliated group, "Najd Province", had claimed attacks on Shi'ite mosques in May that killed 25 people.
IS has committed atrocities in Syria and Iraq, where it controls swathes of territories, and expanded across the region, claiming responsibility for a wave of deadly attacks from Libya to Kuwait.