At least 50 people were hurt when a Boeing 787 operated by LATAM Airlines dropped abruptly mid-flight from Sydney to Auckland on Monday, according to the airline and a New Zealand health service organisation that treated the injured.

The aircraft landed at Auckland airport as scheduled on Monday afternoon, according to FlightAware.

“LATAM Airlines Group reports that flight LA800, operating the Sydney-Auckland route today, had a technical event during the flight which caused a strong movement,” the carrier said.

One person is in a serious condition while the rest suffered mild-to-moderate injuries, a spokesperson for Hato Hone St John, which treated roughly 50 people at the airport, said.

“The plane, unannounced, just dropped. I mean it dropped unlike anything I’ve ever experienced on any kind of minor turbulence, and people were thrown out of their seats, hit the top of the roof of the plane, throwing down the aisles,” passenger Brian Jokat told the BBC.