RIYADH: The Islamic State group pledged to destroy Saudi Arabian prisons holding militants after Riyadh’s execution of 47 people including 43 convicted al Qaeda militants on Saturday.

An article in an online magazine posted on Tuesday singled out the al-Ha’ir and Tarfiya prisons where many al Qaeda and Islamic State militants have been detained. In July, an Islamic State supporter killed himself in a car bomb at a checkpoint outside Ha’ir prison near Riyadh.

Saudi Arabia executed 47 people on Saturday for terrorism, mostly suspected al Qaeda members but also a prominent Shia cleric, signalling it would not tolerate attacks by either Sunni extremists or minority Shias seeking equality in the kingdom, but stirring sectarian anger across the region.