Manchester United will launch an investigation to determine how Rangers fans got tickets in the home section for Thursday’s Europa League tie at Old Trafford.

The club have vowed to take the “strongest possible sanctions” against any registered holders who sold tickets to Rangers supporters.

United said: “All examples of away fans in home areas will be investigated over the coming days, with the strongest possible sanctions taken against the registered holders.

“In anticipation of the risks around tonight’s game, we took the strictest possible measures to prevent sales to away fans in home areas.

“Tickets were only allocated to people who existed on our database prior to the draw taking place in August. Hospitality tickets had the same restrictions applied.

“Tickets forwarded by season ticket-holders and members also had the same restrictions applied – that is, they could only be forwarded to fans on our database prior to the draw.

“Whilst the unauthorised touting of tickets has become more difficult since our introduction of in-app digital ticketing, it cannot be completely eliminated.”

Before kick-off, there were reports of rival fans clashing in the Ancoats area of central Manchester and social media posts later appeared to show confrontations between United and Rangers supporters in the home sections, with some of the Scottish club’s followers chanting “your city is blue”.

There was sensitivity over Thursday night’s fixture – dubbed the ‘Battle of Britain’ – following the scenes of mayhem in central Manchester when the two clubs met in 2008. The damage caused to the city centre at the time was described as the worst it had sustained since the Blitz in World War Two.

British clubs also had to beef up security at stadiums following the widespread hooliganism before and during the Euro 2020 final at Wembley between England and Italy.