The Kingdom of Saudi Arabia executed 37 men Tuesday for terrorism related crimes. Among those killed, 11 were accused by authorities for spying on behalf of Iran. Fourteen were convicted for violent offenses pertaining to prior anti-government protests.

Most of the convicts identified as Shia and were predominantly from the country’s majority Shia eastern province. Most of the defendants were arrested between 2011 to 2012. One was arrested when he was 16 years old.

Amnesty International has criticized Saudi Arabia for human rights abuses, including the country’s disregard for the rights of minors, the use of the death penalty and lack of due process. Amnesty reports the Kingdom utilized torture and interrogations to secure forced confessions. Families of the victims were not notified of the executions. Amnesty said Saudi Arabia’s executing of children under the age of 18 is against international human rights laws. It also reports three individuals under the age of 18 currently remain on death row.