Arvalee Special School fire: No definite cause found
No definite cause for a fire that destroyed a County Tyrone special school has been found, the police have said.
Forensic officers and police carried out a detailed examination of the scene at Arvalee Special School in Omagh, following a blaze on Friday night.
Further samples have now been taken for analysis.
But the police said there had not been any "breach" of the school or its perimeter.
One hundred and three pupils had been due to return to the school on Monday morning.
Principal Johnathan Gray said staff and pupils were devastated by what had happened.
The fire destroyed about 75% of the building and there were fears for the safety of the remaining structure on Deverney Road.
Some of the school's pupils arrived at the gates with their families on Saturday morning, and many were visibly upset by the damage to the building.
The school opened in September 2004, after the amalgamation of Heatherbank School and Cranny School.
It specialises in working with pupils aged three to 19 years of age who have moderate and severe learning difficulties.