LONDON — Britain scrambled a Royal Air Force Typhoon jet on Wednesday after a commercial airliner entered restricted airspace put in place for the London Olympics, the Ministry of Defence said.

The RAF jet was launched after air traffic controllers lost contact with the plane.

But contact was soon re-established with the jet and the Typhoon was called back to base.

A Ministry of Defence spokeswoman said: "We can confirm that 1 Typhoon launched shortly before 11:30 am today.

"This was in response to a commercial aircraft that was out of communication with air traffic control services. Communications were quickly restored; no further action was required."

Britain has mounted its biggest peacetime security operation to guard the Olympics, which officially open on Friday.