A Saudi court on Tuesday sentenced 15 people to death for spying for Iran, Saudi-owned al-Arabiya television reported.
The 15 were among 32 people — comprising 30 Saudi Shia Muslims, one Iranian and an Afghan — who were detained in 2013 on charges of spying for Iran and went on trial in February.
There were no immediate details on the outcome of the trial for the remaining 17 suspects.
Saudi state media reported in February that those charged were accused of establishing a spy ring in collaboration with Iranian intelligence and providing Iran with highly sensitive information on the Saudi military.
The reports said they also were charged with seeking to commit acts of sabotage against Saudi economic interests, inciting sectarian strife, recruiting others for espionage and participating in anti-government protests.
Diplomatic tensions have been high between Shia power Iran and the Sunni-ruled kingdom of Saudi Arabia all year long.