A woman's arm and ankle bones were broken when she and a man were attacked on a Hastings roadside at the weekend.
Detective Sergeant Stacey Bailey said the 31-year-old woman and a 25-year-old man were standing on the corner of Riverslea Rd North and Alexandra St early on Saturday morning when they were attacked by four or five people.
The assailants, three or four males and one female, leapt out of a car that stopped after driving past.
There was no obvious reason for the attack and the victims could not provide a description of their assailants.
The woman was awaiting surgery to fix her broken bones. The man she was with had been discharged from hospital.
Police said they wanted to speak to the occupants of a white car that was in the area at the time and have appealed for any witnesses to call them.
"There was some traffic in the area at the time so we are hoping that someone may have seen either the victims or the white car around 1.30am on Saturday in Riverslea Rd North or Alexandra St,'' said Bailey.
She said anyone with information could call her on 06 8310700 or leave information anonymously on Crimestoppers 0800 555 111.