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.

In the Metrojet plane attack on October 31, an air mechanic whose cousin joined ISIS in Syria is suspected to have planted a bomb on the Russian passenger plane at the Sharm el-Sheikh airport. The plane then exploded in Egypt’s skies after takeoff, killing all 224 aboard.

Egypt’s military wrote on its Facebook page that its airstrikes also killed 45 ISIS fighters and ammunition depots used by the group, Reuters reported.

Egyptian forces have been battling Islamic militants in Sinai for years but the insurgency there has grown deadlier since the 2013 ouster by the military of the country's Islamist president.

The Associated Press contributed to this report.