Dyfed-Powys Police is investigating a fatal microlight aircraft collision which happened near Cwmbach near Builth Wells.
The incident occurred just before midday on Sunday.
Two men died in the incident.
Next of kin have been advised and are being supported by police family liaison officers.
HM.Coroner has been advised.
The independent Air Accidents Investigation Branch is also conducting an investigation.
A Welsh Ambulance Service spokesperson said: “We were called shortly after midday yesterday to reports of a light aircraft collision in the Cwmbach area of Builth Wells. We sent a paramedic in a rapid response car, a crew in an emergency ambulance and an ambulance officer to the scene.”