Ramzan Kadyrov, the Kremlin-backed leader of Russia's Chechnya region, has vowed to kill whomever was responsible for the beheading of a Chechen man, purportedly shown on an Islamic State (IS) video.
Kadyrov told journalists on December 3 that the man, identified in the video as Magomed Khasiyev, was a Chechen.
"We, Chechens do not forget such things, whoever did it to the man will be killed too," Kadyrov said.
On December 2, a video was released online showing the beheading of a man whom the extremist group said was a Russian spy.
It is the first video from IS concerning alleged Russian spies since Moscow began hitting Syria with air strikes on September 30.
In January, the group released a video purporting to show a young boy shooting dead two men accused of working for Russian intelligence services.
There was no immediate comment from Russia's Foreign Ministry or its FSB federal security service.
Based on reporting by Reuters and Interfax