RIYADH: Four security officials have been killed when a suicide bomber detonated a device near the security headquarters of Masjid-i-Nabvi (PBUH) in Madinah, one of Islam's holiest sites, a Saudi-owned television channel reported on Monday.

The news channel showed images of fire raging in a parking lot and reported the initial death toll in Madinah as five, which includes the suicide bomber and four security officers.

Two other bombers also blew themselves up earlier Monday on opposite sides of the kingdom.

According to media reports, suicide bombers struck three cities across Saudi Arabia on Monday, in an apparently coordinated campaign of attacks as Saudis prepared to break their fast. The explosions targeting US diplomats, worshippers and a security headquarters at a mosque.

A witness said one explosion destroyed a car parked near a mosque, followed by another explosion just before 7 p.m. local time. Photographs purporting to be of the incident published on Twitter showed a severed leg and crowds gathered outside a mosque at dusk.

It further stated in foreign media reports that a suicide bomber has blown himself up near Faraj al-Imran Mosque in Saudi city of Qatif. Only the suicide bomber is killed in the attack, according to Arab media. This was the third suicide attack in Saudi Arabia on Monday. Earlier the day a suicide bomber detonated his suicide vest near the US consulate in Jeddah.

A suspected suicide bomber has died after blowing himself up near the United States consulate in Saudi Arabia's city of Jeddah. Security officers early on Monday became suspicious of a man near the car park of Dr Suleiman Faqeeh Hospital, which is directly across from the US diplomatic mission.