Saudi Arabia announced on Saturday it had executed 47 prisoners convicted of terrorism charges, including al-Qaeda detainees and a prominent Shia cleric who rallied protests against the government.
The execution of Sheikh Nimr al-Nimr is expected to deepen discontent among Saudi Arabia's Shia minority and heighten sectarian tensions across the region.
Meanwhile, the execution of al-Qaeda militants convicted over deadly bombings and shootings in Saudi Arabia raised concerns over revenge attacks. The extremist group's branch in Yemen, known as al-Qaeda in the Arabian Peninsula, threatened violence against Saudi security forces last month if they carried out executions of members of the global network.
Saudi Arabia's top cleric Grand Mufti Sheikh Abdulaziz Al Sheikh said the executions were carried out in line with Islamic law and the need to safeguard the kingdom's security. He described the executions as a "mercy to the prisoners" because it would save them from committing more evil acts and prevent chaos.
http://www.cbc.ca/news/world/saudi-arabia-executes-nimr-al-nimr-1.3387125
i dont know what the reason is saudi arabia executed their own evil forces..