From antiwar, Soaring Unrest After Saudis Execute Top Shi’ite Cleric:
Nimr was detained in 2012 for his role in organizing a protest demanding an end to discrimination against the Shi’ite minority in Saudi Arabia. Nimr’s detention was already wildly controversial, and he was reportedly tortured while in custody.
In Iran the response was more straightforward, as Shi’ite demonstrators marched on the Saudi Embassy in Tehran. The situation got out of hand before long, however, and the embassy was set on fire, leading the Saudis to condemn Iran as “terrorists.”
Iran and Saudi Arabia (SA) are already conflicting in Syria and Yemen. SA has broken off diplomatic ties with Iran.