FIREFIGHTERS are tackling a huge blaze at a derelict primary school building in Great Lever.
The former Clarendon Primary School, Clarendon Street, went up in flames just after 6pm tonight.
Emergency fire crews — standing in for striking firefighters — are still trying to bring the fire under control.
Police have cordoned off the surrounding streets and have advised nearby residents to shut their windows and doors.
The roof is believed to contain asbestos, which could be harmful.
Slates are sliding off the burning roof and the gable ends are unstable.
Area manager Warren Pickstone, from the fire service, said: "When we arrived the fire was already well established.
"It is too early to say what caused it but we know it started in the roof.
"We are trying to make the area as safe as we can and contain the fire.
"At the moment there are flying slates and unsecure gable ends.
"It is a dangerous site."
Residents say the large Victorian building has become a target for vandals since it became derelict about five weeks ago.
Fire crews believe the blaze could have been started deliberately.
Danielle Unsworth, aged 20, from Great Lever, said: “We saw the smoke from another area and came over to see what was happening.
“We could see the roof burning and then the roof started to fall down. It was terrible.”
Sarah Parkinson, aged 19, from Halliwell, said: “I couldn’t believe how much smoke there was.
“All we could see was it collapsing and all of the flames.”
One resident, who asked not to be named, added: “It’s really scary. I have a family and a baby. We’ve been told to stay in our house and shut all the windows.”
An aerial platform arrived at the scene at about 8pm so firefighters could try to tackle the fire from the roof.
Several streets around the building have been cordoned off.