Police are trying to identify two boys seen playing at a derelict shelter damaged by fire last night.
Fire broke out at the old former pavilion above Hillside East, Rothbury, at 6.30pm.
Inquiries are continuing to identify two boys, aged around 12 and 10, playing at the pavilion before the fire started.
Sgt Graham Vickers sad the incident is not being treated as deliberate arson, but as accidental or careless damage.
The landowners have been informed and will remove the debris and secure the fencing around the area.
Anyone with information is asked to ring 101, quoting log 1105 (06/06/15).