SHOCKING videos of the fire which ravaged the Glasgow School of Art have gone viral on Twitter.

The online footage captured by revellers in the city cente have shown the ferocity of the blaze when it was at it's worst.

The fire has caused "extensive" damage at Glasgow's famed Mackintosh Building and hit multimillion-pound restoration work carried out in the aftermath of a previous blaze.

Crews were called to the building in the city centre at around 11.20pm on Friday and were met with "extremely difficult conditions".

Less than an hour later, flames and smoke were belching into the night sky - with more than 150 firefighters eventually deployed at the scene.

Witnesses to the blaze were left horrified and in disbelief that this could happen again to the iconic building.

Below are a selection of videos that show the full scale of the blaze: