Drones came within metres of hitting aircraft over Detling - twice in the space of a month.

Reports from the UK Airprox Board (UKAB), which monitors near misses, show two incidents involving the remotely operated devices, both recorded as being a "category A" risk - the most serious type of near-miss.

In June an autogyro out on a training flight was passing over Detling at 1500ft when a drone passed on its left side just 20m away.

The instructor managed to slow the aircraft and take photos of the drone which were used by investigators to identify the model - though the operator of the drone was never found.

Another incident happened in July, when the pilot of a commercial airliner reported seeing a "helicopter type" drone pass 60ft below his left wing at a height of 4,000ft.

Again, no trace of the drone owner was found.

The UKAB report states: "The drone operator was not entitled to operate there, and his non-compliance posed a safety risk."

The news comes days after a Boeing 757 carrying up to 300 passengers had a near miss with a drone moments after departing Manchester Airport.

According to information published by UKAB there were five incidents involving drones between May and July this year.

Last month transport minister Robert Goodwill said the government is in the early stages of discussion about launching a "drone traffic management system" to regulate the use of the devices, as well as the rollout of an online application to track and manage small drones.

A public consultation will be launched on the issue in spring 2016.

But under the "dronecode" recently published by the Civil Aviation Authority (CAA), there are already clear guidelines in force. The guidance states that recreational drone owners must not fly higher than 122m and should always keep their craft in their line of sight, about 500m (1,640ft).

Drones carrying cameras or similar equipment have to keep 50m away from people and cannot approach closer than 150m to crowds.

Already, two drone operators have been prosecuted by the CAA. One man, Robert Knowles, flew his drone over a nuclear submarine facility. Another, Mark Spencer, flew his over Alton Towers.