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RIYADH, July 4 (Xinhua) -- The suicide bomber who caused a blast near Prophet Mohammed's mosque in the Saudi city of Medina on Monday killed 4 police officers and seriously injured four others, Al Arabiya local news reported.

The bomber targeted the parking lots of the emergency forces vehicles in the west side of Medina near the grand mosque while policemen were having their fast-breaking meal.

He told them that he want to join them for food before blowing himself up.

No official information was released from the Saudi Interior Ministry yet, but this blast was the fourth reported in different Saudi cities on Monday.

The day started with a suicide bomber blowing himself in Jeddah at a parking lots of a hospital, in which two security men were injured.

Twin blasts were reported in Qatif near a mosque, and the worshipers escaped unhurt.

The worst was in Medina as there were thousands who were at the grand mosque during the blast and the police shot near mosque to avoid any stampede by scary worshipers.