The skies above the Israeli town of Hadera were abuzz with delivery drones on Wednesday as national authorities tested a central control room for safely coordinating the small pilotless aircraft with each other as well as with planes and helicopters.

The popularity of the cheap, low-flying drones, and their potential for ferrying anything from pizzas to prescription drugs between businesses and homes, has stirred fears of mid-air collisions or crashes that could cause casualties on the ground.

“This is an opportunity for the regulators to learn what is needed to establish delivery drones as a daily reality, and for the drone operators to learn what is expected of them in turn,” said Hagit Lidor of the Israel Innovation Authority, one of several state agencies involved in the test.

In the first live trial of a two-year test phase launched in January, rural Hadera’s airspace was turned over to five private firms that flew drones on criss-cross runs designed to test the responses of a control room in the city of Haifa, 56 km (35 miles) away.

To keep the drones - which went up 20 at a time - no more than 120 metres (yards) above ground and no less than 60 metres (yards) apart, the control-room staff sent alerts and rerouting instructions to their operators electronically.

“For the first time, we are managing airspace as a single entity, synthesising drone operators with established civil and military aviation,” said Lidor.

She added regulated commercial drone deliveries in Israel were unlikely before 2023, when the testing is due to end and related matters like legislation would have to be addressed.

Organisers said helicopters or planes were not a planned part of Wednesday’s trial but may be involved in a follow-up in June. Piloted aircraft more commonly seen at low altitudes around Hadera are crop-dusters and paragliders. The drones were told to steer clear of these by at least a 1 km (half a mile).

All of the drones were equipped with parachutes, to ensure safe landings should they suffer malfunctions, Lidor added.