A suicide bombing on Friday, May 22, 2015 at a Shia mosque in Qatif, in eastern Saudi Arabia, has killed dozens. In this photo, Shiite Muslim worshippers bleed as they perform self-flagellation to mark the Ashura festival in Qatif on Dec. 27, 2009. Reuters/Zaki Ghawas

A suicide bomber attacked a Shiite mosque in eastern Saudi Arabia during Friday prayers leaving several people dead, Reuters reported. The explosion took place at the Imam Ali mosque in a village in Qatif province, located east of the capital Riyadh.

A witness reportedly said that at least 30 people have been killed in the attack on the mosque where over 150 Shiite Muslims were praying. No group has so far claimed responsibility for the bombing. The mosque was targeted as worshippers were commemorating the birth of a revered figure among Shiite Muslims, the Associated Press reported, citing an activist.

"We were doing the first part of the prayers when we heard the blast," Kamal Jaafar Hassan, one worshipper, told Reuters.

The Saudi state news agency confirmed the explosion, and photos posted on social media showed bodies of victims at the scene.

Saudi Arabia's minority Shiite population, which is mostly concentrated in the country's east, have protested for greater rights in the Sunni-majority country.

In November, an attack on a Shiite religious procession killed at least seven people. Saudi officials reportedly blamed the attack on militants linked to the Islamic State group, which condemns Saudi Arabia’s ties to the West.