RIYADH, Saudi Arabia (AP) — A suicide bomber targeted a mosque in eastern Saudi Arabia as worshippers were commemorating the 7th century birth of a revered Shiite figure on Friday, the Interior Ministry and residents said.

Habib Mahmoud, managing editor for the state-linked Al-Sharq newspaper in Qatif, said that the local Red Crescent authorities confirmed to him that 19 people had been killed and 28 wounded.

There was no immediate word from the Interior Ministry on casualties. The area is heavily populated by members of Saudi Arabia’s Shiite minority.

Saudi Arabia’s Interior Ministry initially reported that an explosion struck a mosque in the eastern province of Qatif after Friday prayers, without providing further details. It later confirmed that a suicide bomber who hid the explosives under his clothes was behind the attack.