A major fire has broken out at a Glasgow School of Arts building that had just undergone a four-year refurbishment.

Firefighters were tackling a serious blaze at the institution’s Mackintosh Building, the school said.

Social media users posted video of huge flames engulfing the historic building and smoke billowing into the night sky on Friday night.

Scotland Fire and Rescue Service told The Independent some 15 fire engines were sent to the blaze after it was reported at 11.19pm.

Fire gutted the building in May 2014 and a multi-million pound restoration project had been returning the famous art school to its former glory.

Witness Aidan Dick said the fire and smoke grew in intensity “in the space of a few minutes”.

He tweeted: “Glasgow School of Art is on fire again. Heartbreaking. My thoughts go to all students and staff, and I hope no one was caught in the blaze.”

Shadow Scottish minister Paul Sweeney, the Labour and Co-operative MP for Glasgow North East, tweeted: “Devastated that a major fire has broken out at the Glasgow School of Art tonight.

“The Mack has been undergoing restoration since the last devastating fire in 2014. @scotfire-glasgo are doing everything they can to salvage the most architecturally important building in Glasgow.”

The building was designed by Charles Rennie Mackintosh and completed in 1909.

Scottish First Minister Nicola Sturgeon said: “This is clearly an extremely serious situation. My first thoughts tonight are for the safety of people – but my heart also breaks for Glasgow’s beloved GSofA.

“Once again, we are indebted to the bravery of our firefighters and other emergency services.”

As of about 1.45am on Saturday, no casualties had been reported, the BBC cited SFRS as saying.

Additional reporting by PA