Thirty-one passengers have been injured after a Jakarta-bound flight encountered "severe and unexpected turbulence" about 45 minutes prior to landing, UAE's Etihad Airways said on Wednesday.

The Abu Dhabi-based airline's flight EY474 was bound to Soekarno Hatta International Airport when it was hit by the turbulence, Etihad said in a statement.

The Airbus A330-200 aircraft landed safely at the airport and passengers were met by medical teams, it added.

Twenty-two passengers are being treated for minor injuries at the airport, while nine others have been taken to a local hospital, it said.

As a result, flight EY475 from Jakarta to Abu Dhabi on Wednesday has been cancelled, it noted.