Four people have been killed while 18 others injured including two policemen when a suicide bomber blew himself up and another opened fire outside a Shiite mosque in eastern Saudi Arabia's al-Ahsa region in Eastern Province.

No serious injuries were reported, the Saudi Interior Ministry said Friday, adding an explosive belt and two machine guns were seized with the attackers.

The Security forces prevented the suiciders before entering the mosque where worshippers were holding Friday prayers, the ministry said.

A bomber blew himself up as the security teams engaged him. The other attackers exchanged fire with the forces.

The gunman was shot injured and taken into police custody wearing an explosive belt, the ministry added.

Source: MENA