'Smoke bomb' Builth Wells High School set to reopen
A school that was closed when a "suspected smoke bomb" was set off will be able to reopen after police handed back the keys to the head teacher.
About 20 people suffered breathing difficulties during the incident at Builth Wells High School in Powys on Wednesday.
A 16-year old boy was arrested and has been released on bail while investigations continue.
Supt Jon Cummins said he hoped the community could "get back to normal".
All buildings were evacuated but paramedics found those staff and students affected did not require further treatment.
While the school remained closed on Thursday and Friday provision was made for students taking exams.
'Increased police presence'
Dyfed-Powys Police, who attended the scene alongside paramedics and fire crews, said it was treating it as an isolated incident, which was not believed to be terrorist related.
A school statement published in the Powys County Times referred to a "suspected smoke/sulphur bomb".
Supt Cummins added: "I'm pleased to draw this part of the investigation to a close so parents, children and local communities can get back to normal.
"This has caused significant disruption and I'd like to thank the whole community for their support while we safely deal with the incident.
"The town may experience an increased policing presence, which should not cause any alarm - this is merely to reassure and support following this incident."