A passenger plane was forced to drop sharply to avoid a mid-air crash with a NATO jet, Russia has claimed.

The commercial propeller aircraft was flying off Russia's east coast when it was forced into performing the emergency action, according to a security source in the country.

Air traffic controllers spotted the two planes approaching one another as the Russian Aurora Airlines flight - a subsidiary of Aeroflot - was making its way from Sakhalin peninsula to the Kuril Islands, reports in Russia claim.

A Russian passenger plane run by Aurora Airlines (file picture) was forced to drop sharply to avoid a mid-air crash with a NATO jet, Russia has claimed

It was forced to make an emergency descent when the unknown jet entered its 'air corridor', according to the Interfax news agency.

Authorities are said to have made attempts to contact the unidentified military aircraft, but did receive a response from their radio signals.

But the Moscow Times reports that the jet's radar transporter was recorded and that a security source said it belonged to a NATO aircraft.

The claim has not been confirmed.

It comes at a time of heightened tensions between Russian president Vladimir Putin and the West. 

There have been few recent examples of NATO planes violating Russian airspace, but frequent reports have surfaced of Putin's jets being intercepted by Western jets.