The image of the Glasgow School of Art in flames drew reaction from architects and art lovers who described its destruction as an international tragedy.

Historians, politicians, writers - and singer Lily Allen - also mourned the damage to the Charles Rennie Mackintosh building.

Allen tweeted: "Oh no! This Glasgow School of Art fire is devastating" while broadcaster Andrew Neil wrote: "Deeply saddened that this international cultural treasure is on fire."

Travis lead singer Fran Healy, who joined the band on the day he enrolled at the art school in 1991, wrote on the micro-blogging site: "Just super super sad this place which has been with Glasgow and with all the students is burning down..."

Architect and presenter of Channel 4's The Restoration Man, George Clarke, tweeted: "Devastating to see the Glasgow School of Art in flames...I'll support it's full restoration in any way."

Antiques Roadshow expert Steven Moore wrote: "Seeing Glasgow School of Art on fire is heartbreaking. Its like watching a dear friend in agony & you're unable to help. I feel sick."

Armando Iannucci, the Glasgow-born creator of the political satire The Thick Of It, who attended nearby St Aloysius College said: "So sad to hear of the fire at Glasgow School of Art. I went to school across the road from it. A great building."

Actor Colin McCredie, who played DC Stuart Fraser in detective drama Taggart, tweeted: "I feel as if a little part of Glasgow has died today."

Crime writer Ian Rankin wrote: "Just heard about devastating fire at Glasgow School of Art - one of Scotland's most iconic buildings. Sad sad news."

Pulitzer-prizewinning architectural critic Paul Goldberger wrote on the micro-blogging site that it was terrible news for "one of our greatest buildings".

Art critic Josh Spero said: "The Glasgow School of Art is one of my favourite buildings and a C20 landmark. I hope that the damage is as little as possible."

Singer Eddi Reader wrote that she was praying nobody was injured in the fire.

Historian and broadcaster Matthew Ward wrote on Twitter: "The destruction of any library or seat of learning, whether by accident or malicious design, always leaves a scar on civilisation."

He later added: "One of the Crown Jewels of Scotland, CRM's [Charles Rennie Mackintosh's] library of @GSofA now nothing but ashes and memories

The BBC's arts editor Will Gompertz said the fire was terrible news and represented a "horrible blow to a great city."

Meanwhile, the National Trust for Scotland [NTS] offered its help. It tweeted: "Shocked at the fire at Glasgow School of Art. NTS offers its help and assistance if needed. Hoping for the best."