Saudi Arabia names Egyptian accomplice in Shia mosque attack

The interior ministry identified the second assailant, who was disarmed and arrested at the scene, as Egyptian national Talha Hesham Mohamed Abdu.

"[Talha] arrived in Saudi Arabia on a family visit visa, accompanied by his parents, on 31 July 2013," the ministry said in a statement on Monday.

The Egyptian attacker is currently under tight security watch in a hospital where he is undergoing treatment.

During Friday prayers last weekend, two gunmen wearing suicide bomb belts attacked the Imam Redha Mosque in the Mehasin neighbourhood, an area popular with Shia workers of state-run Aramco, the world's largest oil-producing firm.

The first attacker, identified by the ministry as 22-year-old Saudi national Abdul Rahman Abdullah Sulaiman al-Tuwaijri, detonated his explosives, while Talha opened fire on the worshipers.

No group has claimed responsibility for the attack, which left at least four people dead and 18 others injured.

The Friday attack was the latest in a series of assaults against Saudi Arabia's Shias, who make up some 10 to 15 percent of the ultra-conservative, Sunni-ruled kingdom's population.

In October 2015, the Islamic State militant group claimed responsibility for a suicide bombing at a mosque in the Saudi city of Najran. The attack left at least two people dead and 12 others injured.

Security authorities continue to investigate and prosecute anyone suspected of being involved in the incident, according to the ministry's statement.