Owners of the West Pier in Brighton today vowed to carry on with restoration despite the second arson attack in a matter of weeks.

Scores of people watched as flames leapt from the pier's stricken concert hall during the small hours of yesterday morning.

At the end of March, crowds had also gathered at the historic landmark as fire ripped through its theatre, leaving nothing but a burnt-out shell.

Both blazes are being treated as arson but police have not said whether they are being linked.

There are reports that a man was seen climbing on to the pier shortly before yesterday's fire, which started just after 2am.

Firefighters found piles of burning rubbish and wood inside the concert hall.

After the first blaze, a man who called himself Piers Burns contacted The Argus to claim responsibility, saying he was protesting about the conflict in Iraq.

As they surveyed the damage, the pier's owners were in a sombre yet defiant mood.

Geoff Lockwood, chief executive of the West Pier Trust, said: "I said last time it was either gangsters, fanatics or anarchists.

"The fact fire has been reported in several places looks like it was a professional job. I think someone is deliberately trying to sabotage the pier. I don't think it's a random amateur anarchist."

He was determined the restoration would go ahead next year as planned.

He said the greatest damage was to the public perception of the project rather than to the pier itself.

He said: "If the fire had not been caught in time, it might have had a greater impact. We still want to save the west wall of the concert hall.

"If the wind had gone the other way, we would have been very disappointed because we would have lost a lot of material we are hoping to salvage."

Mr Lockwood blamed legal battles for the delay in restoration and said it meant the pier was in a much worse state than it should have been.

He said: "I am very angry. If we had stood here two years ago and looked at the pier, it was almost intact. We were taking the public round for tours.

"Yet here, two years later, it has been hit by a number of disasters. That pier would have been well on its way if it wasn't for the lawyers."

Delays have been caused by objections from the Noble Organisation, owners of the nearby Palace Pier, who say National Lottery cash should not be used to fund the project.

The latest fire was spotted by a security officer, employed to guard the pier since the first attack, who called the emergency services.

Firefighters from East Sussex and Brighton and Hove laid hosepipes along the narrow walkway connecting the pier to the seafront and were able to tackle the blaze near the concert hall.

Scores of clubbers gathered to watch the spectacle as flames shot out of the collapsed concert hall and the glow of the fire could be seen along the coast.

Fire crews remained at the scene throughout yesterday damping down as small pockets of fire kept flaring up.

Station Officer Ron Kirkwood, in charge at the scene, sent crews as far as possible along the walkway but kept them at a safe distance as they trained hoses on the flames.

Firefighters were unable to run water-supply hoses from hydrants in Kings Road.

A brigade spokesman said: "It would have meant closing the road completely and since there were no reports of people in the fire it was not justified."

As the blaze died down, a fire crew was able to enter the collapsed concert hall and fight the remains of the fire from the safety of the walkway.

Station Officer Danny Sherman, based at Roedean, said: "We are pretty sure the fire was started deliberately because there are several pockets of fire. It's a shame someone does seem to have it in for this particular structure."

Dozens of residents and visitors poured on to the beach during the day to take a look at the smouldering building.

Many took photos while others grabbed burnt embers from the water as souvenirs before the area was cordoned off by city council workers.

Visitor Chris Davey said: "It's a shame such a great piece of Brighton history is in such a state."

Another onlooker said: "Its terrible. Hundreds of birds evicted after the first blaze found refuge in that building. Goodness knows where they will go now."

Consultant engineers from Helmsley Orrell were called in to inspect the damage.

Engineer John Scatchard said the structure appeared to be stable but he had warned firefighters to get off if they heard any groaning or creaking.

Hove resident Ian Divall, 34, said: "It's a disgrace we are stood here watching this again. It's just very sad that someone is so determined to destroy it.

"I sat here watching it when the back part burnt down and it was heartbreaking. I can't believe it has happened again."

Roger Hinton, chairman of the Regency Square Area Society, said although he had opposed the enabling development to fund the pier's restoration he was shocked it had been targeted again.

He said: "We would have liked the pier to have been restored but not with the enabling development.

"It has reached the stage where it will be a replica rather than a restoration and I don't think £15 million of public money should be spent on a replica. It is time to let it go."

A couple, from Seven Dials, who were sitting on the beach, had differing views.

The man said: "It really is appalling they can't manage to do something about it.

"This is the third time I have been down here and it's a shame because we are losing our heritage. Lots of people have got memories associated with this pier and seeing it burn is like a desecration."

But his wife said: "I do think the people who want to rebuild it are living in cloud cuckoo land. I think some things should be left to go and the expense of trying to keep this pier is just too much."

Barry Nabbs, 20, from Hove, said: "I think it was inevitable after the last time it burnt down that it would happen again.

"It has become such an eyesore and I think people are going to start asking why don't they tear the whole thing down."

Sheila Conachy, from Hove, said: "I think it's a great loss and it's now beyond saving.

It's amazing how people have come to pay homage. I think it's quite a symbol for the community."

A Sussex Police spokesman said the cause of the blaze was being investigated.

He said there had been reports of fireworks being let off on the seafront near the pier before the fire started.

He said: "We have a scenes of crime officer going to the pier and a full health and safety assessment will also be made."

In the last fire on March 28, the theatre at the end of the pier was destroyed.

Although the concert hall was not gutted by yesterday's fire, it suffered successive collapses in storms on December 12 last year and January 1.

The pier was opened in 1866 and is one of only two Grade I listed piers in Britain.

Built by Eugenius Birch, it was immensely popular throughout the Twenties but in 1975 it closed when the structure became unsafe.

For almost 30 years the grand old lady has become increasingly dilapidated as different rescue packages were put together only to fall through.

Finally, councillors agreed plans for a controversial development to pay for the pier's restoration and work was due to start early next year.