The Islamic State group said it was behind the attack in the Shiite-populated Eastern Province of Saudi Arabia that killed and wounded several people during the main Friday weekly prayers.
"Hezbollah holds Saudi authorities totally responsible for this ugly crime," the group said in a statement condemning the bombing.
It accused the ultra-conservative Sunni-majority kingdom of "sponsoring and backing criminal murderers" and of "failing to protect" its Shiite citizens who have long complained of marginalisation.
Saudi Arabia described the attack as a "terrorist" act aimed at undermining national unity.