A Saudi court on Wednesday sentenced 22 Saudi citizens, an American and a Yemeni to jail terms of between two and 27 years on terrorism charges, according to the official news agency SPA, Reuters reported.
The court said charges ranged from "the establishment of a terrorist cell planning to targeting oil pipelines," having weapons, and planning attacks and at home and in neighbouring Bahrain.
The U.S. citizen, who was not identified, was sentenced to 17 years backdated to the start of his detention six years ago for "cyber crimes", the court said without elaborating. He will be deported on completion of his sentence.
Unrest by the Shi'ite minority in the oil-rich kingdom has bubbled since the 2011 Arab uprisings, and Saudi Arabia has lent its support to allies in Bahrain to quash anti-government protests mostly lead by Shi'ites.
Saudi Shi'ites make up between 10 percent to 20 percent of the kingdom's population and live mostly in the Eastern Province, where the biggest oil and gas fields are located.
A small fire broke out at a gas pipeline there on Tuesday when assailiants shot at a police patrol.