Suicide Bomber Attacks One of Islam's Holiest Sites Medina among 3 cities hit By Newser Editors and Wire Services Posted Jul 4, 2016 1:53 PM CDT 109 comments Comments A file photo of worshipers visiting the cemetery outside the Prophet's Mosque in Medina, Saudi Arabia. (AP Photo/ Hadi Mizban) (Newser) – Yet more high-profile terror attacks: Suicide bombers struck three cities in Saudi Arabia on Sunday, including in Medina near one of the holiest sites in Islam. In the latter incident, the explosion took place outside the mosque where the Prophet Muhammad is buried, reports AP. Several cars caught fire, and local media showed images of what appeared to be a fire outside one of the buildings overlooking the Prophet's Mosque. The number of casualties was unclear, though Reuters reports three bombers and two security forces officers were killed. The sprawling mosque is visited by millions of Muslims from around the world each year during pilgrimages to Mecca. The area would have been packed with pilgrims for prayer during the final days of the Muslim holy month of Ramadan, which ends in the kingdom on Tuesday. Also Monday evening, a suicide bomber and a car bomb exploded near a Shiite mosque in eastern Saudi Arabia, several hours after another suicide bomber carried out an attack near the US Consulate in the western city of Jiddah. Neither of those two attacks killed anyone but the bombers. The possibility of coordinated, multiple attacks across different cities in Saudi Arabia on the same day underscores the threat the kingdom faces from extremists who view the Western-allied Saudi monarchy as heretics and enemies of Islam. Saudi Arabia is part of the US-led coalition fighting the Islamic State group in Iraq and Syria. The violence follows attacks in Iraq, Bangladesh, and Turkey.