Alwaght- Four people have been killed in an attack on a police station in Saudi Arabia's central Riyadh province.
According to local media reports, the four casualties had helped carry out the attack at the police station in Zulfi, a small city around 250km northwest of the capital Riyadh.
Unverified videos circulating on social media showed a car at a checkpoint with its doors open and two bloody corpses splayed on the ground nearby. Gunshots could be heard.
Witnesses say the attackers had been carrying machine guns, bombs and petrol bombs.
Armed groups have targeted security installations for years in Saudi Arabia, the world's top oil exporter, after the authorities crushed an uprising of members of al-Qaeda more than a decade ago.
Last year, a member of the security forces and a Bangladeshi resident were killed in an assault on a security checkpoint in nearby Buraidah and a policeman was killed in a separate attack in the western city of Taif.
There is simmering insurgency inside Saudi Arabia amid an ongoing brutal crackdown on dissent by the Riyadh regime led by its de facto leader Crown Prince Mohammad bin Salman
Saudi Interior Ministry has not commented on the attack and no group has claimed responsibility.