Five people died when a gunman attacked a Shiite gathering hall in eastern Saudi Arabia on Friday, Saudi state television reported.
ISIL claimed responsibility for the attack in an online statement.
The attacker, who was shot by police, “was in his twenties”, according to Al Ekhbariya TV. His motives remained unclear.
A resident of the eastern city of Saihat said the attacker approached the hall in a taxi but was stopped at a checkpoint.
Police arrived and a gun battle broke out, which the resident said injured several people and left the gunman dead.
Amateur video from inside the hall showed worshippers in flowing black and white robes, including children, crowd towards the entrance to hear the gunfire before retreating.
ISIL had launched a series of deadly attacks in the kingdom in recent months. A suicide bomber killed 15 people in an attack on a mosque in south-west Saudi Arabia in August, while in May, two suicide attacks on Shiite mosques killed 25.
Since the attacks, volunteer security guards have sprung up at holy sites in the kingdom’s largely Shiite Eastern province.