Saudi troops (file)
Saudi troops (file)Reuters

Riyadh orchestrated a major crackdown on Islamic State (ISIS) over the weekend, the Saudi Interior Ministry announced Saturday, arresting some 431 people associated with the group. 

Of those, some 190 people have been linked to attacks on Shiite mosques in May which killed dozens of worshippers, according to Al-Arabiya. 144 were due to be tried on charges of helping ISIS indirectly. 

Saudi authorities also seized an enormous cache of evidence, including documents, communication tools, explosives and weapons.

37 people died during the crackdown and 120 people were injured, both from security forces and civilians. Six were terrorists. 

Thousands of Saudis have been estimated to have joined ISIS over the past two years; the group has declared Saudi Arabia a target - despite the fact that the country employs a strict version of Sharia law - because that interpretation of the law is not up to ISIS standards.

Concerns have grown so high over ISIS that Riyadh may have repaired tenuous ties with Hamas over the issue, after delegations from the two met this weekend for the first time since 2013.