The patrol was targeted while on duty yesterday in the neighbourhood of Al-Musara, killing Corporal Abdullah Treiki al-Turki and wounding six other police officers, the interior ministry said, cited by the official SPA news agency.
The ministry blamed the attack on "terrorists", without giving any further details.
The attack occurred in the same area where a policeman was killed and three others wounded in a bombing on Tuesday morning.
Three people, including a police officer, were also killed last month in bombings in Qatif, where most of Saudi Arabia's Shiite minority lives.
Authorities have blamed the unrest on "terrorists" and drug traffickers.
Disclaimer: No Business Standard Journalist was involved in creation of this content