Scores of Shiites are on trial in Saudi Arabia after they were detained for involvement in anti-regime protests staged in oil-rich Eastern Province since February 2011.
The two defendants sentenced to death by a court in Jeddah were convicted of "taking part in forming a terrorist group" and "attacking security forces, as well as public and private property," said the official SPA news agency.
One of the two was also found guilty of leading and inciting protests in the restive Shiite village of Awamiya, and firing at security forces, as well as writing anti-regime graffiti on walls, it added.
It was unclear if there were police casualties in any of the attacks for which they were found guilty.
The verdicts are subject to appeal within 30 days.
The same special court issued the first death sentence to a defendant involved in the Shiite protests on May 26, a day before sentencing another protester to death.
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.
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.
