An investigation has been launched after firefighters worked through the night to tackle a blaze which engulfed an entire former school building.

Emergency services were called to the disused Paradykes Primary School in Loanhead, Midlothian, at 9.37pm on Saturday.

They found the building was "well alight" and had been alerted to a possible person trapped inside.

Appliances from Dalkeith, Liberton and Penicuik attended, using pumps and hoses to tackle the flames.

A Scottish Fire and Rescue spokeswoman said: "They fought the fire externally as the building was fully involved."

It was later confirmed there were no casualties and everyone had been accounted for.

Extensive damage was caused to the building and the fire is now being treated as suspicious.

Inspector Neil Mitchell at Dalkeith Police Station said: "We have information that a number of youths were seen in the area near to the building prior to the fire starting.

"We are appealing for anyone who may have been nearby and saw any youths at the building or have information relating to the fire to call us on the 101 number, quoting PS-20171104-4396.

"We are also keen to hear from anyone who may have their own CCTV system in or around the area of Mayburn Walk to get in touch."

Door-to-door inquiries are being carried out and CCTV footage is being sought and viewed.