Greater Manchester Police are appealing for information after a man was dragged out of his car and attacked in a car park in Oldham.
At 7.30pm on Thursday 22 March, police were called to Derker Metrolink Stop on Cromford Street to reports that a man had been attacked.
The man, in his 40s, had just got into a white Vauxhall Corsa, which was parked in the car park, after arriving on a tram from Manchester.
He was dragged out the car by a group of people who then attacked him with a hammer and drove off in the Corsa, in tandem with two other vehicles.
The victim suffered serious head injuries and was taken to hospital for surgery.
Officers want to speak to seven people in connection with the attack who are described as male, Asian, aged between late teens and early 20s and dressed in all black clothing, possibly tracksuits.
Detectives are not treating it as linked to any other incidents but are keeping an open mind about the full circumstances.