A Saudi court sentenced 15 people to death on Tuesday over charges of spying for Iran, Saudi-owned al-Arabiya television reported.
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, Saudi state media reported in February.
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.
The 15 men sentenced to death were among 32 people who were detained in 2013 on charges of spying for Iran. They went on trial in February.
The accused are 30 Saudi nationals, one Iranian and one Afghan national.
No details were released on the fate of the remaining 17 suspects.
Crises in Iraq, Syria, and Yemen have raised diplomatic tensions between predominantly Shia Iran and the Sunni-ruled kingdom of Saudi Arabia.