Many of the victims in Christchurch Hospital will require multiple surgeries, due to the nature of their injuries

Greg Robertson's the hospital's head of surgery and says they initially worked to save lives, dealing with major issues like bleeding immediately and leaving treatment of lesser injuries - meaning some will require surgery three or four times.

Greg Robertson says 12 people are currently in a critical condition, while a 4-year-old girl also remains in a critical condition in Auckland's Starship hospital.