Three people are feared dead after helicopter and plane had a midair collision in the UK.
Both of the aircraft are understood to have come from Wycombe Air Park in Buckinghamshire, just north of London, shortly after midday on Friday (local time).
Air crash investigators have been called to the crash site, in dense woodland, alongside paramedics, firefighters and Thames Valley Police, who said the first priority was "preservation of life".
A spokeswoman for South Central Ambulance Service (SCAS) said: "There have been a number of casualties at the scene, but at this stage this is all we are able to confirm."
Waddesdon Manor, on the Rothschild family-owned estate near the crash site, described the crash as a "tragedy" and added it "did not happen at the manor nor have there been any casualties at Waddesdon Manor".
Waddesdon Manor is managed by the Rothschild Foundation, a family charitable trust, on behalf of the National Trust, who took over ownership in 1957.
RAF Halton, which is nearby, said no military aircraft had been involved.