England supporters were staying in Porto ahead of Thursday's match in nearby Guimaraes against the Netherlands and gathered in the fan-zone to watch Wednesday's match between Portugal and Switzerland on outdoor big screens.
The Guardian reported that hundreds of England fans were baton charged by riot police after they threw beer glasses.
England’s Football Association (FA) last week urged supporters of the national team to stamp out “embarrassing” and anti-social behaviour.
The FA released a video called “Don’t be that idiot” to highlight examples of English hooliganism that have come to light in recent months, ending with a message from England manager Gareth Southgate encouraging supporters to make the country proud by being on their best behaviour.
(Reporting by Simon Evans; Editing by Toby Davis)