Christchurch Hospital has beefed up security after a nurse was attacked on her way to work this morning.
Police are hunting a man wearing a Halloween mask who approached the nurse and pressed what is believed to have been a gun at her head near Hagley Oval cricket ground.
The man approached her from behind at about 6am on Riccarton Ave, police said.
The woman screamed and pulled away, causing the man to run off.
He was last seen running towards Deans Ave.