ISIS says its leader who coordinated attacks on the West has been killed

An ISIS-linked media agency reported Tuesday that one of the group's top-ranking lieutenants has been killed near Aleppo, Syria.

The Amaq agency released a statement declaring ISIS spokesman Abu Muhammad al-Adnani's death. ISIS followed Amaq's statement with an official statement of its own released through its online channels.

Adnani was reportedly responsible for coordinating attacks on targets in the West. He also released propaganda statements on behalf of the group.

Adnani had massive influence inside ISIS.

Click through images of the battles with ISIS and conditions in Mosul:

And he was thought to be a potential successor to ISIS leader Abu Bakr al-Baghdadi if Baghdadi were to be killed.

Adnani's death is a "major blow" to ISIS, according to Rita Katz, a terrorism analyst and the director of the SITE Intelligence Group.

"When calling for lone wolf attacks in [the] West, ISIS fighters/supporters quote Adnani more than any other individual," Katz said on Twitter.

The Bastille Day attack in Nice, France — during which a man killed more than 80 people after he drove a truck into a crowd — seemed possibly inspired by an Adnani statement from 2014 that called on supporters to kill "infidels" wherever they can.

"If you are not able to find an IED or a bullet, then single out the disbelieving American, Frenchman, or any of their allies," Adnani said. "Smash his head with a rock, or slaughter him with a knife, or run him over with your car, or throw him down from a high place, or choke him, or poison him."

In an in-depth report published earlier this month, The New York Times described Adnani's role within ISIS. Aside from being the group's spokesman, he reportedly oversaw a complex and extensive network of secret operatives dispatched to Europe to conduct attacks on targets in the West.

Adnani, who was born in Syria, had been with ISIS since its earliest days. He went to Syria on behalf of the group in 2012, before ISIS seized territory across the Middle East and declared its "caliphate."

Official channels have so far not confirmed the death, but terrorism experts have stated that the statement from Amaq appears legitimate.