France has boosted its deployment of ground-to-air missiles protecting the La Hague nuclear waste reprocessing site.
Missiles were positioned around La Hague on the Normandy coast in northwest France in October as a precaution following the September 11th attacks.
"We are not adapting it to any specific threat, this is a fine tuning," said a spokesman for the army, adding that the waste treatment centre now enjoyed 360 degree cover.
Some 150 military personnel are stationed at three bases around La Hague. An early detection radar system is in place to spot low-flying aircraft.
Defence Minister Mr Alain Richard has also said France was prepared to use warplanes to shoot down hijacked aircraft.
France relies on nuclear power for about three-quarters of its electricity.