Both aircraft involved in the incident belong to private airline companies that cater to tourists and Nepalese in the country's remote areas.
The airport - called the gateway to Mount Everest - is one of the world's most risky because of the short runway and the mountainous surroundings.
There are about 35 flights and 100 helicopter ferries a day from the airport.
Lukla airport is used by climbers heading for the Everest region each and every year.
The airport is named after two men who were first to climb the 8848-metre peak.
At least four persons including Manang Air Pilot CB Gurung have been also been injured in the crash, the report added. The airfield is notorious for its short runway and perilous approach, sitting at an elevation of over 2,800 meters.