In Medina, Islam’s second holiest city after Mecca, the bomber attacked a security checkpoint near the Prophet's Mosque, a security source said on condition of anonymity due to restrictions on speaking to the media.
Two people and the attacker were killed, the source said, as people broke their fast on the last night of Ramadan. There was no official comment on the attack near the mosque, which is the burial place of the Prophet Muhammad.
In the eastern city of Qatif, two suicide bombers targeted a Shia Muslim mosque. There were no reports of casualties.
Another suspected suicide bomber targeted the U.S. consulate in Jeddah earlier Monday, the day Americans celebrated their independence.
In a telephone call to King Salman Bin Abdulaziz Al Saud, Turkish President Recep Tayyip Erdogan condemned the “atrocious” attacks, a presidential source said under condition of anonymity.
Erdogan offered his condolences and wished speedy recoveries for the injured as well as passing on his greetings for Eid al-Fitr.