The Airbus A380 aircraft encountered severe turbulence while on approach to Mumbai. While descending from Flight Level (FL) 380 to FL150, the flight crew observed on the weather radar display a patch of isolated cumulonimbus (CB) clouds near their flight path. In anticipation of the adverse weather ahead, the flight crew turned on the ?fasten seat belt? sign. At about 86nm from Mumbai Airport, the flight crew requested for a heading of 300ø, which would keep the aircraft at least 10nm clear of the adverse weather. The request was approved by ATC. The flight crew recalled that the flight was smooth and calm from the start of descent until the turbulence encounter. When the aircraft had passed the observed weather, the flight crew, on two occasions with an interval of about two seconds, felt some light to moderate turbulence which lasted about one to two seconds each. The ?fasten seat belt? sign had already been turned on but the cabin crew was still preparing the cabin for landing. The Senior First Officer, who was the pilot flying the aircraft, made an announcement through the Public Address (PA) system just before the aircraft encountered the turbulence to instruct the cabin crew members to be seated. Some passengers and cabin crew members were thrown up towards the cabin ceiling and were injured. Four of them suffered serious injury. The occurrence was most probably a case of encounter with clear air turbulence. The aircraft eventually landed in Mumbai Airport and the injured persons received medical attention. The Air Accident Investigation Bureau of India classified this occurrence as an accident and delegated its investigation to the Air Accident investigation Bureau of Singapore.