Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Type 849.00
Flight Deck / Cabin / Aircraft Event Illness / Injury; Inflight Event / Encounter Weather / Turbulence
Weather
In cruise; smooth air; radar was being manipulated to monitor weather as there was scattered activity from after takeoff including deviations and avoidance. Near ZZZZZ we encountered unforecast and unexpected moderate turbulence with a heavy rolling motion while the radar picture showed no convective activity with multiple setting monitored. Two minor passenger injuries; one bumped head in lavatory and one small burn due to spilled coffee occurred while seatbelt sign was off due to previous smooth air. Two minor flight attendant injuries; bumps and bruises resulted in stiffness and soreness but they were able to continue their duties. Preflight weather evaluation including turbulence forecast and radar evaluation showed no adverse weather or Sigmets in or near incident area overwater.
B737 Captain reported minor injuries to multiple passengers and flight attendants after encountering unexpected moderate turbulence.