China Eastern on Tuesday confirmed five passengers and two crew members were injured when flight MU777 encountered high altitude turbulence prior to the plane's descent to Sydney.

"The safety of our passengers is our primary concern and we have confirmed that all of the affected passengers are in a stable condition, having received treatment for their injuries," China Eastern general manager for Oceania Kathy Zhang said in a statement.

The airline said it is attempting to contact the families of those injured, and has set up a hotline - +61 416 791 968 - for any concerned family members of passengers on board.

A spokesman for Australia's Transport Safety Bureau told Xinhua that inquiries are ongoing as to the circumstances of the incident, but there is no restrictions on the aircraft or its crew returning to China.

"If anything abnormal, we will do a further detailed investigation," the spokesperson said.

China Eastern will cooperate with the relevant investigatory authorities, the airline said.