June 16 (UPI) -- A fire has ripped through Scotland's world-renowned Glasgow School of Art, which was under restoration from a fire four years ago, officials said Saturday.
Firefighters battled the blaze Saturday, which ripped through the school's Mackintosh building overnight and had spread to adjoining buildings.
Officials told The New York Times the blaze had "consumed" about half of the building.
No one was injured in the blaze, which also spread to nearby building, including a campus nightclub, Scottish Fire and Rescue Service said.
More than 120 firefighters and 20 fire engines responded to the scene.
Deputy Chief Officer Iain Bushell, in charge at the scene, said the fire caused "extensive damage."
"This is an extremely challenging and complex incident, but the response and professionalism of our firefighters has been exceptional," Bushnell added. "This will be a prolonged incident and crews will remain on the scene as they work to prevent further fire spread and damage."
A cause has not yet been determined, firefighters said.
The building under restoration from a May 2014 fire had been set to re-open next year prior to this weekend's fire.
The restoration project, estimated to cost between $26.5 million and $46.5 million, was aimed at returning the renowned institution to its former glory following the 2014 fire.
A projector exploding in the basement caused the 2014 fire, which damaged the library viewed as on of the finest examples of art nouveau in the world.
Scotland's First Minister Nicola Sturgeon told BBC News that the fire was "heartbreaking," and worse than the one four years ago.
"The fire has been a devastating blaze, much worse than the one that took hold of the Mackintosh building four years ago," Sturgeon added. "The damage is severe and extensive. My heart goes out to everybody associated with the art school."
The building, known as lauded designer Charles Rennie Mackintosh's masterpiece, opened in 1909.