A policeman was shot dead by masked gunmen in the Qatif district in Saudi Arabia's oil-producing Eastern Province on Wednesday, state news agency SPA said, the latest in a string of attacks there this year.

Four assailants opened fire on a police station before dawn, SPA reported.

Qatif, which is both a city and the name of a district, is home to many Shia Muslims, who form a minority in the conservative Sunni Muslim kingdom.

Qatif was one of three Saudi cities targeted in coordinated bomb attacks on July 4. A suicide bomber struck near a Shia mosque killing himself and two others.

The Saudi government said Islamic State was likely behind the attacks. Islamic State, which follows a hardline Sunni Muslim ideology, considers Shias apostates who should be killed