No fewer than four people have been killed after a suicide bomber detonated his explosives at a Shia mosque in eastern Saudi Arabia during Friday prayers.
A witness described a huge explosion at the Imam Ali Mosque in a village in the province of Qatif, where more than 150 people were praying.
An activist told the AFP news agency that at least four worshippers were killed, while a source told the Reuters news agency that there appeared to be at least 30 casualties in the attack.
Pictures posted on social media purported to show the devastation, with dead bodies strewn across the floor and shattered glass covering the courtyard of the mosque.
Al Jazeera reported that authorities expected the death toll to rise.
Saudi Arabia’s Shia population is mostly based in two oasis districts of the Eastern Province – Qatif on the Gulf coast, and al-Ahsa, southwest of the provincial capital al-Khobar.