The leader of the Islamic State’s operations in the volatile Sinai Peninsula and mastermind of the October 2015 attack on a Russian airliner in the region that left 224 dead has been killed by Egypt’s air force, intelligence sources told Fox News Thursday.

ISIS Sinai leader Abu Dua al-Ansari was killed in Al Arish, the sources said.

A post on the Facebook page of the military’s chief spokesman, Brig-Gen Mohammed Samir, said al-Ansari was killed in an operation guided by “accurate intelligence.”

He helped organize ISIS activities in the region including attacks against U.N. personnel in their Sinai base, investigators said.