LONDON: Four people were killed after an aircraft and helicopter collided in mid-air Friday northwest of London, authorities said.
Fire and ambulance services rushed to the scene at 12:06 p.m. GMT (7:06 am EST) near Aylesbury in Buckinghamshire.
According to SkyNews, investigations at the scene near Waddesdon in Buckinghamshire are expected to continue through the weekend and into Monday morning.
Superintendent Rebecca Mears of Thames Valley Police said: "We did a joint response with the fire service, ambulance and now the Air Accident Branch is working with us for a joint investigation while we establish the cause of the crash."
She added that informing the next of kin and supporting them with specialist officers is a priority.
The crash happened in Upper Winchendon, close to Waddesdon Manor, on Friday, though a spokeswoman for the estate said it had not happened on its grounds.
British media reported that both aircraft came from Wycombe Air Park, also known as Booker Airfield, near High Wycombe, which offers flight training.
The plane that crashed, a two-seater Cessna 152, was built in 1982, according to The Guardian. It had flown almost 14,000 hours as of May and had previously suffered substantial damage to its landing gear, propeller and engine after a crash at a Cornish airfield in 1993.
The Air Accidents Investigation Branch is sending a team to investigate a mid-air collision involving an aircraft and a helicopter near #Aylesbury pic.twitter.com/5DKcijq7Cw— AAIB (@aaibgovuk) November 17, 2017
Ambulance crews, ambulance officers and a rapid-response vehicle were deployed, the South Central Ambulance Service said.
"We're aware of a number of casualties following an incident this afternoon," Thames Valley Police said in a tweet.
We're aware of a number of casualties following an incident this afternoon in Waddesdon, Aylesbury.
There were a number of road closures following the incident, which have now been lifted.
We will provide further updates when available.— Thames Valley Police (@ThamesVP) November 17, 2017
The Air Accidents Investigation Branch said it was sending a team to the site of the accident, which is in dense woodland.
The crash took place near Waddesdon Manor, which is managed by the Rothschild Foundation, a family charitable trust, on behalf of the National Trust.
The manor said the crash did not happen at the site and there were no casualties at the manor.
A nearby military base, RAF Halton, also said no military aircraft were involved.