Wellington, Sep 26 (IANS): Authorities have started investigations into how a drone came close to hitting an Air New Zealand airliner above Christchurch city, the media reported on Saturday.

On Friday evening the plane carrying 166 passengers was 6000 feet above the ground. It was climbing out of Christchurch en route to Auckland, Radio New Zealand reported.

The Civil Aviation Authority (CAA) said the sizable red drone passed within 60 metres of the plane's wing tip.

It said the incident was of particular concern as the drone was being operated above the clouds, and therefore an operator on the ground would not have been able to see it.

According to law, drone operators must maintain a clear view of their aircraft at all times.

Air New Zealand said the plane did not need to take evasive action to avoid the drone, but its chief flight operations and safety officer said the company was disturbed by what it described as an emerging trend of reckless drone use.

David Morgan, captain of the plane, said the airline would support any moves to ensure drone operations did not compromise the integrity of airline operations.

He said Air New Zealand's customers and staff were put at risk by the drone.

"This was reckless behaviour by the drone operator, who has so far not had the courage to come forward and address their behaviour with authorities," Captain Morgan said.

Transport Minister Simon Bridges said the incident was being treated very seriously.

The government recently introduced new civil aviation rules to enable sensible use of the technology while protecting third parties on the ground and in the air.