Hezbollah leader Hassan Nasrallah has called the Sunni Islamic State group a “monster” of an organization whose recent growth and expansion is “worrying,” Ynet reports.

Nasrallah warned in an interview with the Lebanese newspaper Al-Akhbar published Friday that the Islamic State — which controls large swathes of territory straddling Syria and Iraq, where it is accused of perpetrating atrocities — presented a danger that “does not differentiate between Shiite, Sunni, Christian, Druze, Yazidi or Arab.”

“The monster is growing all the time. The numbers [of fighters] and the abilities at the Islamic State’s disposal are great and mighty. This worries everyone, and everyone should be worried,” he said.

Hezbollah, a Shiite organization, has been helping Syria’s President Bashar Assad fight the chaotic mixture of rebel groups which have challenged his rule in recent years. The Islamic State, an offshoot of al-Qaeda which was disowned by its parent terror group for its extreme actions, was one such group. It grew greatly in power through the fighting there, aided by thousands of foreign fighters from the West who flocked to join the jihadist fight against Assad.

Nasrallah warned that the group may next seek to gain ground in Jordan, Saudi Arabia, Kuwait and other gulf states.

“If there is a nation that thinks it can support this organization and use it for its own means, when its turn comes, the Islamic State will show no mercy,” he said.

Nasrallah said that while the danger was real, it could be overcome and defeated, but this would demand a serious effort by regional powers. He noted the group’s advance towards Baghdad had been “largely halted.”

Speaking of Israel, the Hezbollah leader said his organization’s experience in Syria helped it in gaining “knowledge and wide possibilities” in offensive as well as defensive tactics, which he said would be used “in any future conflict with Israel.”