The US Federal Aviation Administration (FAA) has revealed that a number of reported collision incidents between aircraft and an unmanned aircraft systems (UAS) could not be verified by the agency.

The FAA recently released a new document featuring a list of pilot, air traffic controller, law enforcement and citizen reports of potential encounters with UAS.

According to FAA, investigations into incidents reported by commercial aircraft pilots has revealed they were caused by either birds or a structural failure.

The report claims that incidents have been caused by a collision with other items, such as wires and posts, but the involvement of drones or unmanned aircraft has not been proven.

"The Drone Manufacturers Alliance expects all our members’ customers to fly safely, responsibly and far away from aeroplanes and helicopters."

However, FAA’s new document showed that reports of potential encounters between a commercial drone and an aircraft have increased over time.

The reports shows that there were 1,274 reports of possible aircraft-drone collisions from February up to September 2016, compared with 874 for the same period in 2015.

The Drone Manufacturers Alliance, an organisation that represents manufacturers of civilian drones, has expressed satisfaction over the new report published by FAA.

Drone Manufacturers Alliance director Kara Calvert said: “Reputable analyses of FAA data show that many ‘possible drone sightings’ turn out to be perfectly legitimate drone flights, or objects that clearly are not drones, and we expect these latest reports will show the same pattern.

“The Drone Manufacturers Alliance expects all our members’ customers to fly safely, responsibly and far away from airplanes and helicopters.”

The organisation also noted that its members are working with the FAA to develop technologies that could improve drone flight safety.