Drive-by shooting kills Saudi police officer in restive east

Saudi Arabia's Interior Ministry says a drive-by shooting has killed a police officer in the kingdom's restive east.

The Interior Ministry said on Wednesday that four masked men open fire on the officer in the Qatif region in the kingdom's Eastern province. It says an investigation into the shooting was underway.

There's been unrest in Saudi Arabia's predominantly Shiite east since the January execution of a prominent Shiite cleric.