IS vows to destroy Saudi prisons after mass executions

The Islamic State group vowed to destroy Saudi prisons containing jihadi prisoners after Saudi Arabia executed 47 prisoners on terrorism charges on Saturday.

In an online statement released on Tuesday, IS mentioned al-Hair and Tarfiya prisons, where many al-Qaeda and IS supporters have been detained.

"The Islamic State always seeks to free prisoners, but this will not happen except with the eradication of the rule of tyrants, and then destroying their outside the prisons and razing them to the ground," said the IS statement.

The Saudi government said that 43 of those executed on Saturday were al-Qaeda members, however it is unclear whether militants connected to IS were part of the group.

IS has claimed responsibility for a number of bombing attacks against Shia mosques and shootings targeting security services in Saudi Arabia over the past year.

In July, an IS militant also drove a car laden with explosives into a checkpoint outside the Hair prison near the capital, Riyadh.

Saudi Arabia has cracked down on alleged members of the group, arresting 431 individuals it said had links to IS during the summer.

The Saudi government said that 37 people, including a number of Saudi security forces, were killed in the apprehension of the suspected militants.

They had planned to attack mosques and government buildings, according to Saudi authorities.

On Tuesday, fighters attacked a Saudi military position near the country's border with Iraq's Anbar province, killing three Saudi soldiers.

While IS has yet to claim responsibility for the attack, analysts believe it carries the hallmarks of an IS attack, and the Saudi ministry of interior described the attackers as "Kharijites" - a terms it uses to refer to al-Qaeda and IS militants.