Firefighters extinguished the blaze at a waste water treatment plant at the Bacton gas terminal run by Royal Dutch Shell within hours but the plant remained closed on Thursday evening and the extent of the damage was unclear.

'The fire has now been extinguished and the plant has been shut down safely,' Shell said in a statement.

Large quantities of gas from several big North Sea fields that usually flow through the terminal on the east coast of England were still locked out at 5.10am Singapore time, more than three hours after Shell shut the plant down, data from network operator National Grid showed.

Gas suppliers waited for Shell to assess the damage, with colder weather forecast for next week threatening to test supplies of heating fuel if the terminal cannot reopen soon.

Short of about 13 per cent of the gas that National Grid expected to be needed to meet heating and power generation, British suppliers turned to the Rough storage facility to make up for it, with flows from there jumping by about 50 per cent.

'Rough is responding,' a spokesman for operator Centrica said. 'This clearly shows the importance of storage to the UK.'

The Centrica spokesman said the storage site under the North Sea, which feeds into a different terminal further north, could run at the rate it was being used at for about a month.

Of the five supply lines that enter Britain's gas network through the Bacton complex, only two were affected by the fire.

At its height, 10 fire engines were tackling the blaze which broke out shortly before 2am Singapore time. There was no information on any injuries or on the possible cause of the fire.

About 40 per cent of Britain's power is generated by gas and most of its homes rely on it to keep warm in cold weather. -- REUTERS