BEIJING — A Shanghai TV station has acknowledged that footage of a formation of 2,000 drones flying over the city broadcast on New Year's Eve had actually been prerecorded days before.

The footage had been the highlight of Dragon TV's holiday gala and presented as occurring live. News organizations including The Associated Press published the video.

However Shanghai residents said they had witnessed no such event, prompting the network to issue a statement saying the event was rehearsed and recorded on Dec. 26 and Dec. 27 because of safety concerns about the size of the crowd along the city's famous riverfront Bund on New Year's Eve.

"Due to the high crowd at the Bund on New Year's Eve, watching the drone show may cause safety problems, so the rehearsal and recording time of the drone was moved forward," the station said in its statement.

The decision was likely informed by memories of a Dec. 31, 2014, stampede on the Bund in which 36 people were killed and 49 injured when a crowd of 300,000 gathered to watch a light show. Several city officials were fired or otherwise reprimanded over the tragedy.

Large crowd sizes in China during holidays are a regular worry, resulting in everything from crushing deaths to massive traffic jams.