Locals called 999 at about 1 o’clock this afternoon when they saw flames shooting up to 40 feet into the air from the disused school.

Five fire engines were immediately sent to the scene where they are continuing to fight the fire.

A spokesman for Strathclyde Fire Brigade said: “The fire is not yet under control. It’s quite a substantial fire and is still burning.”

A local chaplain suggested that the fire may be the work of vandals.

Rev Dr James K Torrens, who is a minister at St Rollox Church of Scotland and former chaplain at Sighthill Primary, said: “I saw the flames shooting at least 40 or 50 feet into the air. There is a suspicion that it may have been caused by vandals, because we have had problems like that in the area. The school closed in the summer and there have been repeated acts of vandalism since then.”

He added: “I spent this morning with a former teacher from the school. Mr Hugh McArthur. He would have been very sad to see the building go up in flames.”