BEIRUT, November 17. /TASS/. Militants of the terrorist organization Islamic State (IS) have beheaded 15 Syrian soldiers together with captive American Peter Kassig, the Al-Watan newspaper reported on Monday. Several pilots of the Syrian air force who had been taken prisoner on August were among the executed, the report says.

The execution of Peter Kassig, a US aid worker and former Army Ranger who was captured last year in Syria while on a private humanitarian mission, was confirmed by the White House Sunday. Kassig is the third US citizen beheaded by Islamic State terrorists.

Islamic State has previously released videos of the beheading of two US journalists, James Foley and Steven Sotloff. The militants have also beheaded two British aid workers, David Haines and Alan Henning and French citizen Herve Gourdel. The group says the killings are revenge for the ongoing, US-led air campaign against its fighters in Syria and Iraq.