Ramzan Kadyrov, the head of the Republic of Chechnya, has issued a menacing warning to Turkey via his Instagram page after Turkish forces shot down a Russian warplane near the Syrian border.
Kadyrov, who is usually more likely to post videos of him doing martial arts, uploaded a clip showing him walking on a treadmill while wearing a t-shirt emblazoned with an image of Vladimir Putin, a missile and a fighter jet.
In the video, Kadyrov promises that Turkey will "regret what it has done for a very long time," adding: "Those who take every opportunity to talk about friendship and coooperation should not act so underhandedly."
Previously described by this newspaper as the 'Warrior King of Chechnya', Kadyrov has a close relationship with the Kremlin, and some unusual personal tastes.
He keeps a lion and a tiger as pets, has been known to hand out 1,000-rouble notes freely to citizens as he travels around the country, and has a fleet of luxury cars.
Oddly, he was once a former Chechnyan separatist rebel, who fought against the Russians - before changing allegiances at the start of the second Chechen war in 1999.
His comments were sparked by an incident on 24 November, in which a Russian warplane was shot down by Turkish forces, apparently for briefly crossing into Turkish airspace.
At least one of the two crew members on board was shot dead as he parachuted to the ground. The fate of the other is still unclear.
President Putin has called the shooting down a "stab in the back" from Turkey, and warned there would be "serious consequences" for Turkey.
