Severe turbulence left 30 people injured and many passengers fearing for their lives on a flight from Istanbul to New York.

Dozens of ambulances were called to New York’s John F Kennedy international airport after those on board the Turkish Airlines flight were tossed around the plane cabin during the unanticipated episode around 45 minutes before landing.

Injuries included a broken leg, and cuts and bruises, with one passenger reporting blood smeared on the overhead luggage compartment.

Passengers said the turbulence was not announced and some people were not wearing their seatbelts at the time.

“We were fearing for our lives,” said Derya van Helden, who travelled on the flight on Saturday.

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“Even when we had the seatbelts fastened, everyone was screaming for their lives,” she added.

Steve Coleman, a spokesperson for the Port Authority of New York and New Jersey, said a flight attendant had broken her leg during the turbulence.

Passenger Sead Nikaj told ABC News: “Nobody announced it or anything like that so we figured out something was wrong.

“Then I see people start flying on the plane. Then seeing blood all over. I had one of the ladies next to me, she really fell down from her seat on the floor and all her back was completely bloody, while someone that was working in the aeroplane, she cracked her leg I think completely.”

Another passenger, Amir Mehrbakhsh, said some people hit their heads on the ceiling after they were lifted from their seats by a sudden drop caused by the turbulence.

He said he saw one man frantically screaming: “I think he was like doing a religious chant. I kept hearing him say ‘Jesus’, like he was visibly distraught.”

Turkish Airlines confirmed the turbulence in a statement released early on Sunday, saying it was “deeply saddened by this unfortunate experience, and [will] closely monitor the health status of injured passengers, and is making resources available to them”.

The airline said there were 326 passengers and 18 crew members on the flight.