A group claiming links to Islamic State (IS) on Saturday said it carried out the attack on a Shia gathering in Saudi Arabia which left five people dead and nine others wounded.
The killings come two days after the start of Ashura commemorations, the interior ministry says.
The interior ministry said a gunman opened fire at random before police intervened and shot the attacker dead.
Later, a group calling itself Islamic State-Bahrain State said that one of its soldiers had attacked a Shia infidel temple with an automatic weapon.
The group warned that infidels will not be safe in the island of Mohammed.
