The New Zealand accident investigator said Chilean authorities had confirmed they had opened a probe into the flight, and it was assisting with their inquiries.

At least 50 people were hurt, mostly with minor injuries, after LATAM Airlines told the New Zealand Herald that a “technical problem” had caused a “strong movement” during a flight from Sydney to Auckland on March 11.

A spokesperson for TAIC said because the incident on the Sydney-Auckland flight on Monday occurred in international airspace it fell to Chilean accident investigation authority Direccion General de Aeronautica Civil (DGAC) to open an inquiry.

“TAIC is in the process of gathering evidence relevant to the inquiry, including seizing the cockpit voice and flight data recorders,” the New Zealand agency said, referring to the so-called “black boxes” that will provide more information on the flight’s trajectory and communications between pilots.

DGAC said in a statement it was working with TAIC on the investigation.

LATAM did not immediately respond to a request for comment on whether it had given the black boxes to TAIC. The airline said earlier on Tuesday it would assist the relevant authorities on any investigation.

The airline and passengers aboard the flight said on Monday the plane with 263 passengers and nine crew members on board dropped abruptly mid-flight.