Taliban spokesman Zabihullah Mujahid has confirmed Mullah Omar’s death on Twitter. While the death appears to be a major blow for both al Qaeda and the Taliban, Islamic State forces are believed to have benefited from it.

The supreme commander of the Taliban died in April 2013. The news was first confirmed by the Afghan government. The Taliban extremists apparently wanted to pretend that Omar was still alive, even publishing a statement in his name a few weeks ago. However, it later seemed to agree that the reports were correct.

Analysts believe that Omar’s death is an existential crisis for the Afghan Taliban, News24 reported. The death will definitely trigger a power struggle within the organization, according to observers.

ISIS should welcome Omar’s death, which will eventually be helpful to the terrorist organization led by Abu Bakr al Baghdadi. Baghdadi claims to be the caliph, while al Qaeda considered Omar the "Emir of the Believers."

Al Qaeda mastermind, Osama bin Laden, too believed in Omar’s leadership. “My pledge of allegiance to the Emir of the Believers [Mullah Omar] is the great pledge of allegiance, which is mentioned in the chapters of the Koran and the stories of the Sunnah,” The Daily Beast quoted bin Laden as saying in a video recorded before 9/11. “Every Muslim should set his mind and heart and pledge allegiance to the Emir of the Believers Mullah Muhammad Omar, for this is the great pledge,” he said.

Al Qaeda disowned ISIS and its leader in February 2014. Since then, ISIS has been competing with its militant counterpart for supremacy in the Middle East. Baghdadi demands all the militant groups in the region, including al Qaeda, to be loyal to his leadership.