A major fire has broken out at a large building in Camden Lock Market in London, sending flames climbing high into the night sky.

Eight fire engines, an aerial ladder and about 60 firefighters were initially sent to the area after the first emergency call just before midnight on Sunday, London Fire Brigade said. However, this was quickly increased to 10 fire engines and 70 firefighters.

On its Twitter account, the brigade appealed to the public to "please avoid the area".

"A building within the market is alight and part of its first, second and third floors are affected by the fire, as well as part of its roof," it said in a statement on Facebook.

"Crews from Kentish Town, Euston, Soho, Paddington and Holloway fire stations are at the scene.

"The cause of the fire is unknown at this stage."

At 3am, a brigade spokesman told The Independent that fire crews were involved in "damping down" of hot spots but that the fire had not yet been officially brought "under control".

An eye-witness, Joan Ribes, 24, said she had called the police, urging them to close a nearby street to traffic "because it was very dangerous".

"The fire was flying through the air to the surrounding areas," she said.

"The fire was moving very fast. People were watching, but we were scared the building could explode at any time since there are restaurants with kitchens nearby."

Numerous photographs on social media showed the fire was well alight with the flames towering high above the surrounding buildings.

One witness tweeted: "On a night bus I just passed the start of a big fire in Camden, now at Euston I've seen lots of ambulances head north."

Another said: "Just drove past Camden market and there's a huge fire on top a building, close to the Loch Bridge! Crazy, crazy scenes."

And blogger Jo Brodie wrote: "Gosh it's awful. I sincerely hope no-one hurt - such a busy part of London at all hours."

There are more than 1,000 shops and stalls at the market, which is well known as a centre of social life for many people in this part of north London. It normally closes at 7pm.

The Metropolitan Police said officers were in attendance at the scene.

"Police were called on Monday at 12.10am to Camden Lock Market to reports of a fire. London Fire Brigade were already at the scene when officers arrived. It is unknown at this stage if any persons are injured, we await update," a police spokeswoman said.

London Ambulance Service said it was called about the fire at 12.07am.

“We sent a clinical team leader and our Hazardous Area Response Team (HART) to the scene," it said in a statement.

“We have not treated any patients, and we remain at the scene.”

The market was hit by a devastating fire in 2008, which led to fears for its future and for the hundreds of people who work there.

News of a new fire at the market saw headlines on media outlets from around the world, including CNN in the US, Russia Today, Canada's CTV, Australia's 9News and Italy's La Repubblica.