An attack by gunmen on Saudi police patrolling a Shiite village in oil-rich Eastern Province on Tuesday wounded one policeman and caused a pipeline to catch fire, an official said.
The patrol came under "heavy gunfire" in Awamiya, scene of past clashes between Shiite protesters and security forces in the Sunni-dominated kingdom, police spokesman Colonel Ziad al-Ruqaiti said.
The dawn attack triggered a "limited fire at a nearby pipeline," while a policeman was shot in his leg, he said, without specifying the significance of the pipeline.
The region sits on the bulk of Saudi oil wealth, which amounts to about one-fifth of the world's proven oil reserves.
Demonstrations in Eastern Province, where most of the kingdom's two million Shiites live, erupted in 2011 alongside a Shiite-led protest movement in neighbouring Bahrain.
They turned violent in 2012 and clashes between police and protesters have reportedly killed 24 people, including at least four policemen.
Two people were sentenced to death in June, while a third was jailed for 25 years after being convicted of violence during Shiite protests.
In January, the US embassy warned its citizens against travel to Awamiya after gunmen opened fire on the car of two German diplomats, who escaped unhurt.
Of more than 950 people arrested in Eastern Province for involvement in the Arab Spring-inspired unrest, 217 are still being held.
Short link: