Armed police are to guard Bacton Gas Terminal against a possible terrorist attack, Norfolk Police has confirmed.
One quarter of Britain's gas is handled at Bacton
The decision to deploy armed police is part of an ongoing review of security around the country.
Norfolk Police aims to improve the safety and security of staff and nearby residents at the Bacton site.
The Home Office emphasised it had not received any intelligence of an attack, or an increase in the level of terrorist threats.
A national newspaper claimed there were intelligence reports of al-Qaeda suspects showing an interest in some oil and gas terminals.
But the Home Office said: "We have been very clear that we face the severe threat of terrorism, so it is important that we consider all options to protect our assets and infrastructure.
"This particular review doesn't reflect any specific threat. We constantly keep our resources under review."
One quarter of Britain's gas is handled at Bacton, which also processes supplies from three North Sea oil fields and channels gas to and from Europe.