A Nato fighter jet "buzzed" a plane carrying the Russian Defence Minister as it flew over the Baltic Sea, before being seen off by a Russian military jet, Russia said, an account partly disputed by Nato.
A video of the altercation broadcast on a TV channel run by Moscow's Ministry of Defence showed an F-16 flying parallel with Sergei Shoigu's plane at a short distance.
A Russian Sukhoi-27 fighter was then seen to insert itself between the F-16 and the minister's plane, before dipping its wings to one side to show the missiles it is carrying.
The F-16 then left the area. It was not clear which air force the F-16 belonged to.
Nato said it had tracked three Russian aircraft over the Baltic on Wednesday, including two fighter jets which it said did not respond to air traffic control or requests to identify themselves.
"As is standard practice whenever unknown aircraft approach Nato air space, Nato and national air forces took to the sky to monitor these flights," a Nato official said.
"When Nato aircraft intercept a plane they identify it visually, maintaining a safe distance at all times. Once complete, Nato jets break away," the official added.
The alliance said it had no information about who was on board the planes.
Mr Shoigu's plane had been en route to the Russian exclave of Kaliningrad for a meeting to discuss how well Russia's western flank was defended. Footage of what happened was filmed by someone on his plane.
The RIA news agency reported that Nato aircraft had also tracked Mr Shoigu's plane when he returned after his meeting later on Wednesday, albeit at a greater distance.
The Kremlin has said in the past that all Russian flights over the Baltic are conducted in strict accordance with international law.
Russian politicians called the episode the latest in a string of "provocations," a day after the Russian defence ministry said an RC-135 US reconnaissance plane had swerved dangerously near a Russian fighter jet over the Baltic and that another RC-135 had been intercepted.
The Pentagon disputed that, saying the US aircraft "did nothing to provoke this behaviour" and that the Russian intercept had been unsafe.
In another episode, Sweden said it had called in Russia's ambassador for talks after a Russian fighter jet buzzed a Swedish military jet on an electronic intelligence gathering mission over the Baltic on Monday.
"The Russian plane's actions were out of the ordinary ... in terms of the distance between the planes which was at certain times very small," the Swedish military said in a statement.
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