The anti-jihadist international coalition in Syria said Sunday it had targeted in a strike an Islamic State 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 IS leader, Abou al Oumarayn... in the desert" in Syria, said Sean Ryan, spokesman for the US-led coalition.
The leader "was implicated in the murder of American citizen... Peter Kassig", kidnapped in Syria in 2013 and executed by decapitation in November 2014, he added.
He was also "directly implicated in the execution of a number of other prisoners", Ryan said, adding that coalition air strikes "continued to disrupt the command and control of IS on the battlefield".
Peter Kassig, aged 26 at the time of his death, founded a humanitarian organisation in 2012 and adopted the name Abdul Rahman after his conversion to Islam.
The international coalition intervened in Syria and Iraq in 2014 to fight the expansion of IS after it had taken control of vast swathes of territory straddling the two countries.
Defeated in Iraq, the group still retains territory in some parts of the Syrian desert, particularly in the east of the country, where the coalition continues to fight the jihadists with the support of an alliance of Kurdish and Arab fighters.