Twenty-year-old twin brothers in Saudi Arabia allegedly murdered their mother for trying to prevent them from joining the Islamic State in Syria — a case of radical Islamic ideology swallowing up Saudi Arabia’s already extreme Wahhabism.

“The only thing (we have established) is that they (the twins) follow Takfiri ideology,” Saudi Interior Ministry spokesman General Mansour al-Turki told Reuters. Takfiri is a phrase indicating militant Islamism. “The case is still under investigation,” he said.

The brothers, Khaled and Saleh al-Oraini, are currently in custody. They reportedly stabbed their mother, father and 22-year-old brother in Riyadh. They tried to cross into Yemen following the stabbing, but were picked up and arrested by Saudi authorities.

The mother later died due to severe injuries.

“Had this come from drug addicts or ignorant youth, it would not have been unusual,” Saudi writer Mohammad Ali al-Mahmoud told Reuters. “The shock is that it came from a pair of religious children acting in the name of Islam.”

The Saudi public is left paralyzed as the attack is the fifth case of suspected Islamic State-aligned members killing relatives in a single year.

It also provokes deep questions about the limits of radical Islam in a country known for funding and developing Wahhabism, which for a long time functioned as the limits of extremism. That limit was breached with the emergence of ISIS.

For ISIS, reverence and respect for parents seems to take the backseat to militancy and the command to kill apostates, even if they’re close family members.

Suicide bombers recently launched attacks in Saudi Arabia at the end of Ramadan. While it’s not clear if they’re ISIS-inspired, what seems apparent is that they’re the result of radical Islam spiraling out of control in a country known for fostering this type of ideology.

Saudi authorities have pushed religious leaders to condemn ISIS as a deviant sect of Islam, but in doing so, Saudis have painted a target on their back.

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