He has been described as operating as a "trusted lieutenant" of the leader of al-Qaeda, Ayman al-Zawahiri with whom al-Masri worked in Sudan and Afghanistan.

According to a statement that Sulaiman Abu Ghaith gave to the Federal Bureau of Investigation, four al-Qaeda leaders were first jailed in an Iranian intelligence building in Tehran for approximately one year and eight months.

[6] Reports surfaced on 26 February 2017 that al-Masri had been killed in a U.S. airstrike in his car in Al-Mastumah in the Syrian province of Idlib.

[6][11] Guardian journalists Tom McCarthy and Martin Chulov later reported that jihadist leaders confirmed that al-Masri was killed in the drone strike.

[2][1] A US intelligence official and al-Qaeda later confirmed that al-Masri had been killed in the strike, which used a variant of the AGM-114 Hellfire missile.