The Saudi Interior Ministry which confirmed the attack said that the bomber targetted Shiite mosque in the Eastern part of the country.
Mansur al-Turki, the ministry’s spokesman, said in Riyadh that the suicide bomber blew himself up outside the mosque in the province of Ihsa when police prevented him from entering.
Al-Turki said that another would-be suicide bomber was arrested after being injured in a shootout with security forces outside the Imam al-Reda mosque.
A security official said three worshippers were killed when police exchanged fire with an unidentified gunman, who attempted to break into the mosque in the Shiite dominated Ihsa area.
Police spokesman said that the attack occurred as worshipers were leaving the mosque following the Friday congregational prayers.
No one has claimed responsibility.
In recent months, there had been series of attacks on mosque in the Shiite minority area of Saudi Arabia.
The attacks were claimed by radical Sunni Islamic State militia.
Sunni extremists regard Shiites as heretics, deserving death. [myad]
