A specialized court in Riyadh gave the first brother 10 years in jail, while his brother received four.

A specialized court in Riyadh has sentenced two Egyptian twin brothers on Tuesday to 14 years in jail for planning a suicide attack on a Saudi mosque in cooperation with ISIS.

The first brother was tasked by ISIS to attack a mosque in Saudi Arabia using an explosive suicide belt, but differences with an ISIS commander in Syria made him retreat from carrying out the attack. He received 10 years in jail, while his brother received four.

The two 30-year-old brothers, whose identities have not been revealed, were arrested by Saudi authorities in Mecca 17 month ago.

Details of the Mosque’s location and the exact timing of the planned operation have yet to be revealed by security officials.

Since mid-2014, the militant group has carried out a series of bombings and shootings in Saudi Arabia that have killed scores of people, some of whom were members of security forces.