At least three were killed in a mid-air collision involving an aircraft and a helicopter in Buckinghamshire, United Kingdom, on Friday.
The helicopter was part of Heli Air's fleet and was believed to be carrying two persons. The plane was a light aircraft with just pilot onboard, said reports.
At least seven fire tenders and several fire officers were rushed to the spot where the wreckage fell.
There is no official confirmation of the death toll. The Telegraph quoted Thames Valley Police as saying that there were a "number of casualties".