About 90 drones have plummeted from the sky and plunged into Sydney’s Darling Harbour during an aerial drone show, prompting a second event to be cancelled later in the evening.

Vivid Sydney said “unforeseen technical difficulties” occurred during Monday’s 7.30pm performance of the show, called Star-Bound, resulting in 89 drones falling into the water at Cockle Bay in Darling Harbour. No injuries have been reported.

The show has cancelled four performances on Tuesday and Wednesday as a precaution to allow the operators to complete a full technical and safety review.

Skymagic, the operator of the drone show, said the performance experienced a technical issue after an “unforeseen change in the radio frequency (RF) environment occurring after take-off”.

“This anomaly caused a number of drones in the fleet to enact failsafe landing procedures in response to compromised positional accuracy,” the company said.

“The pilot team encountering the issue immediately performed a stop command rendering the fleet stationary in the air, enabling time to safely assess the issue. Once stability had been evaluated, the team then activated the return to home protocol bringing the unaffected drones to a safe landing.”

Skymagic said none of the drones left the safety boundary of the show.

“Some vehicles during the emergency landing phase encountered the geofence boundary and shut down to preserve the safety zone resulting in them falling into the water,” it said.

Vivid said in a statement Monday night that “public safety and security remain the absolute priority,” with Monday’s 9.30pm performance cancelled after advice from specialist operators.

“We apologise for the disappointment and thank everyone for their patience and understanding,” Vivid said.

The chief executive of Destination NSW, Karen Jones, which runs Vivid, told ABC Radio Sydney while it was “incredibly upsetting” the shows had been cancelled, safety protocols worked as planned.

“There was an exclusion zone that was specifically designed for the drone show and it did mean that if there was a technical failure – which there was last night – it meant that the drones either fell into the water or within that exclusion zone,” Jones said.

She would not commit to the shows returning on Sunday – the next scheduled dates – until a full assessment is completed and ruled out deliberate interference with the drones, saying operators had looked into it as a possibility during initial assessments on Monday night.

The Australian Transport Safety Bureau said it has been notified of the incident and was gathering more information.

Star-Bound is scheduled to run Sunday to Wednesday evenings at 7.30pm and 9.30pm for the duration of the festival, although the Vivid website notes the performances are weather-dependent.

“Prepare to experience a performance unlike any you’ve seen before as Star-Bound evolves drone shows from a sequence of singular images, to tell a larger, poetic story: a celebration of life, creation, hope and renewal,” a description of the event reads.

The drone show was scrapped last year amid concerns over crowd control issues but it returned this year heralded as Australia’s “most extensive” event of its kind. It features 1,000, purpose-built drones made specifically for large-scale aerial displays.

In 2023, more than 400 drones fell from the sky into Melbourne’s Yarra River during a light show celebrating the Matildas before the Women’s World Cup, with an ATSB investigation later finding wind conditions were to blame.