Updated: HUNDREDS of people were evacuated as firefighters tackled a major blaze at the University of York.

The alarm was raised at about 12.45pm yesterday when smoke was spotted coming from the roof of the chemistry department at Alcuin Way, which houses teaching laboratories.

Eleven fire crews and an aerial ladder platform were called to the scene and remained there for most of the afternoon as firefighters tackled the flames and investigated the cause of the fire.

The blaze is believed to have started in a cabinet or fume cupboard in the chemistry block. A university spokesman said the site’s safety procedures were put in place.

Firefighters opened up a large area of the roof as they tackled the flames.

Trevor Lund, North Yorkshire Fire and Rescue Service's fire investigation and press liaison officer, told The Press: "There was smoke issuing from the roof. On arrival the fire fighting appliances took action on the first floor dealing with a fire in the fume vent system."

He said the investigation was in the preliminary stages but said: "There are some quite challenging chemicals in the building and we are working to make sure that it is in a safe condition."

He praised staff at the university, saying they had isolated most of the major fire risks and given firefighters clear details on the building's lay out and the risks involved.

A University spokesman said emergency procedures had been activated and everyone was evacuated safely.

He said: “North Yorkshire Fire and Rescue Service attended very quickly and we would like to thank them for the excellent job they did in dealing with the incident. They were assisted by Chemistry staff and the University’s Health & Safety team.”

He said the loss of electricity affected 144 student bedrooms as well as the chemistry department and said alternative accommodation and food would be provided to any students still without power tonight.

He added: “Investigations into the cause of the fire are continuing and the University is working to provide alternative teaching laboratories.”

Firefighters from York, Acomb, Huntington, Selby, Easingwold and Tadcaster were called to the scene.

Matt Davey, 18, a first-year chemistry student, said his lessons in the building this afternoon had all been cancelled.

He said: “We heard it might be something to do with the roof. There were second year chemistry students in there having lectures at the time.”

Video: Tom Herbert