A servicewoman has died at an RAF site, the Ministry of Defence (MoD) has said.
The MoD said the incident took place at RAF Weston-on-the-Green, near Bicester in Oxfordshire.
The BBC has been told that the servicewoman was taking part in a free-fall parachute jump on Friday.
A RAF spokesperson said: "The incident is being investigated and it would not be appropriate to comment further at this stage."
"Our thoughts are with the family, friends and colleagues at this time," the spokesperson added.
RAF Weston-on-the-Green is regularly used as a landing area for parachute jumps from nearby Brize Norton.