A train passenger was rushed to hospital after being hit on the head by a vodka bottle on Saturday.
The 63-year-old woman was struck after a fight broke out between rowdy football fans on the 10.43pm Northampton-bound service from Euston.
The victim continued her journey to Hemel Hempstead with her daughter, but began to feel unwell after leaving the train and was then driven to hospital for treatment.
As a result of the attack, she was left with severe bruising and swelling to her head and shoulders.
The woman – a British national who lives in Spain – was due to return home on Monday, but has had to reschedule her flight because of her injuries.
Investigating officer and detective sergeant Gail McKemmie said: “This was a cruel and nasty attack by the group of football fans, who need to take responsibility for their actions.
“We believe the service may have been busy and I am sure someone will have seen the bottle being thrown.
“The group of football supporters who boarded the train may have been returning from the league two play-off final.”
British Transport Police are urging those who saw what happened to call 0800 40 50 40, quoting B9/LNA of 21/05/2013.