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.