The Kremlin said it sent two Tu-22M3 aircraft, capable of carrying nuclear missiles – including hypersonic weapons of the kind designed to evade air defences – to fly over Belarus on Wednesday
It came after an escalation in hostilities at the border, which saw two groups of migrants crossing into Poland before being detained by officials.
Thousands of migrants from the Middle East, Afghanistan and Africa are trying to get to the EU via Poland, adding to growing concerns of armed conflict grow amid rising hostility between the European Union and Minsk.
Camped in sub-zero temperatures and surrounded by armed guards, water cannons and barbed wire, clashes between migrants seeking entry to the EU and Polish border guards are expected to escalate in the coming days.
The worsening situation has caused alarm across Europe, with the EU accusing Belarus of encouraging illegal migration in revenge for previous sanctions on Minsk over human rights abuses.
There have also been accusations, from Poland, that the crisis is being “masterminded” by Russia to cause another migrant crisis situation within the EU, which the Kremlin denies.