The newspaper said two RAF Tornados from its rapid reaction force took off from RAF base Leeming in northern England to confront the two Tu95 "Bear" bombers after they were shadowed by F-16s from the Royal Norwegian Air Force.

An unnamed RAF spokesman was quoted as saying that the Russian bombers, based near the northern port city of Murmansk in the Arctic Circle, turned back before they reached British airspace.

The Times, which said the incident happened Tuesday, said there was no evidence to suggest it was linked to Britain's planned expulsion of four diplomats over Russia's stance on the Alexander Litvinenko affair.

Russia on Tuesday promised a "targeted and appropriate" response to Britain's move, prompted by Moscow's refusal to extradite an ex-KGB agent suspected of poisoning the outspoken dissident in London last year.

But the daily said it smacked of "old-fashioned sabre-rattling" on the part of the Russian military and revived "the spirit of the Cold War" in the North Atlantic.

No-one at the defence ministry in London was immediately available for comment when contacted by AFP but there were swift denials from Russia.

Air force colonel Alexander Drobyshevsky was quoted by the news agency Interfax as saying: "Claims that Russian bombers were headed for British airspace don't correspond with reality.