Saudi Arabia's king Salman has vowed to punish the culprits who were behind the suicide bombing at a Shiite mosque that killed 21 people, saying that it was a "heinous terrorist attack".
According to Fox News, King Salman's statement came after Islamic State (IS) militant group claimed responsibility for the attack in the village of al-Qudeeh in the eastern Qatif region.
King Salman said that all those who supported, planned and collaborated in the attack will be punished, tried and held accountable.
The bomber was identified as Saudi citizen Saleh bin Abdulrahman al-Qashaami by the Interior Ministry.
The mosque attack was the deadliest since a 2004 Al Qaeda attack on foreign worker compounds.