Syria’s anti-jihadist international coalition said late Sunday it had targeted in a strike an ISIS group leader involved in the execution of American humanitarian worker Peter Kassig and other Western prisoners.

“The coalition forces carried out specific strikes against a high-ranking [ISIS] leader, Abou al Oumarayn…in the desert” in Syria, said coalition spokesman Sean Ryan.

The leader “was implicated in the murder of American citizen… Peter Kassig,” who was kidnapped in Syria in 2013 and executed in November 2014, he added.

– With reporting from Agence France-Presse