The show must go on - that was the message last night after Buckingham Palace was hit by a fire in the middle of the Queen's Golden Jubilee weekend.

The building was evacuated as smoke and flames billowed from the glass roof of a corridor linking the ballroom and the State Apartments.

It is thought to be the first time the palace has been evacuated since the Second World War, and the fire revived memories of the horrific blaze which caused £40m of damage to Windsor Castle in 1992.

Stars involved in rehearsals for tonight's Jubilee pop concert were led away from the stage in the gardens, as the blaze took hold and firefighters fought to stop it spreading.

After about an hour, the fire was extinguished and officials confirmed today's Party in the Palace would go ahead as planned.

No members of the Royal Family were at the palace and the Queen was being kept informed of developments.

Last night, investigations were under way to establish how the blaze started, although fire officials immediately ruled out foul play.

No treasures were believed to have been damaged, while valuable artefacts in rooms surrounding the fire were moved to protect them.

There was water damage to carpets, caused by burst pipes, and a glazed ceiling and a plaster ceiling have been damaged, said the Palace.

At its height, flames and smoke could be seen pouring out from the roof and 20 fire engines attended after the blaze was detected by the Palace's automatic fire detection system at 6.42pm.

One firefighter was taken to hospital after being injured during the fire.

A County Durham family was caught up in the drama.

Paul Smith, his wife Paula and three young children had only just arrived outside Buckingham Palace when fire engines started to hurtle through the gates and smoke began to billow from behind the main facade.

Speaking to The Northern Echo from the scene, Mr Smith, of Brancepeth, said: "We can clearly see the smoke rising from just behind the main facade and police are now moving us all back into The Mall."

He added: "This is certainly not what we expected when we visited the palace but I think our photographs will be more historic than we thought."

Director of the Royal Collection Sir Hugh Roberts was inspecting paintings and other valuable items for damage. Later, the Palace said two pictures were removed as a precaution.

Hundreds of people involved in rehearsals for tonight's concert, including an array of pop stars, were ordered to leave the stage when the fire was reported.

Singer Ozzy Osbourne had just finished a 30-minute set piece and the crew were taking a dinner break when the alarm was sounded.

After a two-hour delay, rehearsals resumed with a determination that the show would go on.

Brian Wilson, whose rehearsal slot had been 6.30pm to 7.30pm, took to the stage to go through a series of Beach Boys classics at 8.45pm.

Artists still to squeeze in their rehearsals last night included Eric Clapton, Steve Windwood, Joe Cocker, Ray Davies, Rod Stewart and finally Sir Paul McCartney.

Access to the palace has been unprecedented in recent days in the run-up to the jubilee celebrations.

A massive music auditorium with stage and stands had been constructed in the gardens. On Saturday, more than 12,000 people attended a classical music concert in the gardens and the same number are expected tonight.