Russia's military said on Monday, February 21 that troops and border guards had prevented a "diversionary reconnaissance" group from breaching Russia's border from Ukrainian territory and that five people had been killed, Russian news agencies reported.

Ukraine rejected the report, calling it fake news, and said no Ukrainian forces were present in the Rostov region where the incident was alleged to have taken place, Reuters reports.

Interfax cited the Russian military as saying that Ukrainian armed vehicles had been destroyed.

The reported incident took place at a moment of extreme tension between the two countries as Russia continues to deny statements from the United States and its allies that it could invade Ukraine at any time.