'This is our Notre Dame!' Copenhagen's historic stock exchange goes up in flames as footage shows the moment iconic ...

Denmark's historic stock exchange has erupted into flames after a fire broke out during renovations in Copenhagen today.

Local media reported a 'large bang' early this morning before the 400-year-old spire collapsed, smoke billowing high above the city as locals reported debris from the 183ft tower crumbling into the street below.

'It's horrible. It was one of the city's most beautiful buildings. I pass by here every day It's Notre Dame all over again,' one bystander told state broadcaster DR, recounting the horrifying blaze at Paris' historic cathedral five years ago this month.

'So sad. An iconic building that means a lot to all of us, I think. Our own Notre Dame moment,' Danish deputy Prime Minister Troels Lund Poulsen posted on Twitter/X.

A large police and firefighting presence remains on the scene around the Børsen building, where scaffolding is seen to have collapsed in the inferno. 

Surrounding streets in the Danish capital have been closed off and commuters urged to avoid the inner city as authorities desperately try to tackle the fire.

Crowds gathered in disbelief to look on as the building appeared to collapse in on itself. The Børsen, once the financial heart of Denmark, dates back as far as 1625.

Jakob Engel-Schmidt, Danish Culture Minister, said that 400 years of cultural heritage had gone up in flames as artifacts were hurried out of the fire.

Smoke billows and flames rise around the scaffolding of the old stock exchange in Denmark

Flames engulfing the Copenhagen's Stock Exchange building, in Copenhagen, on April 16

The iconic spire is seen surrounded by collapsing scaffolding early on Tuesday morning

Smoke engulfs the fragile frame of the spire in Copenhagen, Tuesday, April 16

Locals carry paintings and other objects as a fire burns the old Stock Exchange (Boersen) in Copenhagen, Denmark, 16 April 2024

People gather in disbelief as the historic building goes up in flames, on April 16

A man reacts as the Old Stock Exchange burns in Copenhagen, Denmark, Tuesday, April 16

'This is crazy, I've never seen such a big fire in my life. The fire has grown, more and more serious, it seems to be spreading to a larger part of the building,' a reporter for local outlet Politiken said from the scene. 

Emergency services said they had mobilised 'on a massive scale' to quell the outbreak.

'The fire makes it too dangerous to tackle it from inside the building,' said Jakob Vedsted Andersen, heading the emergency operation.

'Our plan is to block the fire so that it does not spread to the other half (of the building). 

'But what we can only ascertain is that it is a very, very extensive fire, which is developing all the time.'

Brian Mikkelsen, director of Dansk Erhverv, Denmark's Chamber of Commerce, was seen helping the efforts to salvage artifacts from the fire.

Video from the scene showed firefighters battling to rescue historic paintings from the building.

Pictures from the scene showed a group carrying out the monumental 'Fra Kjøbenhavns Børs' painting by PS Krøyer, apparently undamaged by the fire.

'We are currently working on saving everything that can be saved,' director Morten Langager, said in a post to X. 

'This is our Notre Dame, it is our national treasure,' reiterated Elisabeth Moltke, a 45-year-old Copenhagen resident, who watched the blaze. 

Others could not hold back tears as they watched the devastation. 

Peter Hummelgaard, Justice Minister, applauded the efforts of emergency services in working to 'save human life and our historical cultural heritage' in a post on Twitter/X.

There were no reports of injuries. Ambulances attended the scene.

The nearby Christiansborg Palace, now the Danish parliament, was partially evacuated as the fire raged.

'Suddenly there was an announcement that we had to leave the building,' local outlet Berlingske reported shortly after 8am BST.

'It happened quietly, and now we have about a hundred people standing outside.'

Early reports claimed parts of the spire had broken off and fallen onto the street by 7.30am BST (8.30am local time).

Members of an army unit were seen being deployed to cordon off the area, and the Danish Emergency Management Agency was also helping. 

The Stock Exchange is a major landmark in the city, identifiable for its twisting 183ft  'Dragespir' (Dragon Spire) and three crowns on top, representing the three kingdoms of Denmark, Norway and Sweden.

The building was undergoing renovations to restore its original façade and correct errors made during an attempt in the 19th century.

During the 1800s, the building was roofed with copper, as much of the original lead lining was scrapped to produce cannon balls during the Swedish occupation, 1658-59.

The building still contains many wooden structures, according to local media.

The roof, masonry, sandstone and spire of Boersen - built in 1615 and considered a leading example of Dutch Renaissance style in Denmark - was being renovated, said the Danish Chamber of Commerce.

The tragedy comes five years since Notre Dame erupted in flames in Paris during renovation work, on April 15 and April 16, 2019. 

Smoke billows during a fire at the Old Stock Exchange, Boersen, in Copenhagen, April 16, 2024

Smoke rises out of the Old Stock Exchange, Boersen, in Copenhagen, Denmark

Many of the internal structures are still made of wood in the building soon turning 400

People salvage a painting from the historic Boersen stock exchange building which is on fire in central Copenhagen, Denmark on April 16, 2024

Firefighters work at the main entrance of the Boersen stock exchange building on Tuesday

The building, one of the oldest in the Danish capital, was undergoing renovation work when it caught fire this morning

Smoke could be seen towering from the inferno from several streets down

A view of the Old Stock Exchange in Copenhagen, Denmark, January 28, 2019

File photo of the historic Borsen building in Copenhagen, Denmark

File photo. Smoke billows as fire rages at the landmark Notre Dame Cathedral in Paris, April 15, 2019

The building - originally built by Christian IV in a bid to strengthen trading on the continent - came to house the Danish stock market in 1974. 

The Børsen managed to escape a fire at the neighbouring Christiansborg Palace in 1990.

The Dutch Renaissance style building no longer houses the Danish stock exchange, but serves as headquarters for the Danish Chamber of Commerce. 

The Old Stock Exchange is used for conferences and parties, and not open to the public, according to Visit Copenhagen. 

The exact cause of the fire outbreak is currently unknown.