A Red Arrows plane has crashed at an air base with reports the pilot ejected.
An air ambulance was scrambled to RAF Valley on Anglesey in north Wales.
Dramatic pictures show a plume of black smoke at the base as witnesses claimed they saw the aircraft burst into flames.
Two people are believed to have been on board the flight before it crashed although a witness says they saw an ejection.
The RAF said an investigation had been launched into the crash but were unable to go into further details.
An eyewitness told the Daily Post that they saw someone parachute from the plane before it crashed.
They said: “I was sat at Rhosneigr train station waiting for the train and you can see the airfield from there and I was watching the Red Arrow flying because you hardly ever see them and then it looked like it was about to land then next thing I saw was the parachute and then the plane hit the runway and went up in flames.”
A spokesman for the Welsh Ambulance Service said: “We were called shortly before 1.30pm this afternoon to reports an aircraft had crashed at RAF Valley in Holyhead.
“There is an emergency ambulance and a Wales Air Ambulance at the scene.”
RAF Valley is a base used to train UK fighter pilots and aircrew for mountain and maritime operations.
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.”
A spokesman for North Wales Police said they were called at 1.50pm and officers are currently on the scene but were unable to give further information.
A North Wales Fire and Rescue Service spokeswoman confirmed they had been called to an incident involving an aircraft at 1.56pm.
The BBC have reported the aircraft was flying from RAF Valley back to RAF Scampton, Lincolnshire – where they are based – when it crashed.
The famous aerobatic Red Arrows were at the base, where Prince William served as a search and rescue helicopter pilot, preparing for the coming display season.
The Red Arrows, or The Royal Air Force Aerobatic Team, are one of the world’s premier aerobatic display teams.
Based at RAF Scampton in Lincolnshire, all Red Arrows pilots have flown operationally in frontline aircraft before joining the display team.
The Red Arrows team perform at RAF Valley most years as part of a ‘family day’ for the family of servicemen who work at the base.
In total, about 1,500 service personnel, civil servants and contractors work at the site.