Two Russian bombers, capable of carrying nuclear weapons, have been caught flying over British airspace.

  The unwelcome guests spent four hours flying over the Isle of Lewis despite being intercepted by two RAF jets.

  A pair of 111 squadron Tornado F3 fighters took of from RAF Leuchars in Fife to locate the supersonic Tu160 bombers in the Outer Hebrides.

  They shadowed the Russian aircraft as they flew south towards the coast of Northern Ireland and then turned north.

  Wing Commander Mark Gorringe, commander of 111 Squadron, said: "This is not an unusual incident.

  "People may be surprised to know that our crews have successfully scrambled to intercept Russian aircraft on more than 20 occasions since the start of 2009.

  "Our pilots, navigators and indeed all the support personnel at RAF Leuchars work very hard to deliver the UK Quick Reaction Alert Force 24 hours a day, which can be scrambled in minutes, to defend the UK from unidentified aircraft entering our airspace, or aircraft in distress.

  "It's a very important job, defending the UK and helping to keep UK citizens safe."

  After being tailed for four hours, the Russians eventually left British airspace.

  The Ministry of Defence stressed that there was no indication that the planes intended to enter British airspace.