A 16-year-old boy has been arrested for allegedly assaulting a woman outisde Calderdale Royal Hospital in the last of three assaults.
Police are appealing for witnesses to the linked assaults which happened in three separate locations in Halifax on Tuesday, February 7.
The first assault happened between 10.25am and 10.40am as the woman was walking along Commercial Street with a 16-year-old male. He is alleged to have head butted her.
The two then got onto the 503 bus which was travelling to Huddersfield bus station when the male is accused of again head butting her before members of the public intervened.
They then got off the bus at Calderdale Royal Hospital, walked into the car park of the main entrance. It is alleged the male assaulted the woman by grabbing her neck outside the main entrance. Members of the public again had to intervene.
The 16-year-old boy has since been released on bail.
Anyone who witnessed any of the assaults is asked to call PC Vicky Thompkins on 101.