An air ambulance is at RAF Valley on Anglesey in north Wales where the incident happened
A Red Arrows plane has crashed with the pilot ejecting, according to reports.
A spokesman for the Welsh Ambulance Service said: “We were called shortly before 1.30pm this afternoon (Tuesday 20 March 2018) to reports an aircraft had crashed at RAF Valley in Holyhead.
“There is an emergency ambulance and a Wales Air Ambulance at the scene.”
An RAF spokesperson said: “We are aware of an incident today at RAF Valley involving a Hawk aircraft.
“We are investigating the incident and it would be inappropriate to comment further at this stage.”
The Red Arrows are at the base, where Prince William served as a search and rescue helicopter pilot, preparing for the coming display season.