London - England's football association branded the unruly behaviour of some English fans in Portugal an "embarrassment" ahead of the Three Lions' Nations League semi-final against the Netherlands on Thursday.
Travelling fans clashes with police and were seen hurling bottles in Porto on Wednesday night with fears there could be further trouble in nearby Guimaraes where Gareth Southgate's side take on the Dutch later today.
Portuguese police said two England fans were arrested on Wednesday after bottles were thrown as crowds watched Portugal's 3-1 semi-final win over Switzerland in a fan zone in the city.
"The FA strongly condemns the scenes witnessed in Porto overnight. Anyone responsible for these disturbances cannot be seen as true England supporters and are not welcome in football," the FA said in a statement.
"They are an embarrassment to the team and the thousands of well-behaved fans who follow England in the right way."
Following similar scenes in recent away England away games in Amsterdam and Seville, the FA had instigated a campaign called "Don't be that idiot" ahead of the four-team Nations League finals in northern Portugal.
However, that call for a clampdown on anti-social behaviour appears to have fallen on deaf ears.
Numerous England fans were also seen urinating in the streets and chanted songs referencing the second world war and the IRA.
"It is completely unacceptable. The behaviour we are witnessing is incredibly disappointing," said Deputy Chief Constable Mark Roberts, the National Police Chiefs' Council football policing lead.
"Again I would point fans towards the recent video from the FA - 'Don't be that idiot'.
"The behaviour of a small number of the England fans out here continues to tarnish the reputation of the genuine fans who are simply trying to enjoy the football."
Over 100 arrests were made when England last met the Netherlands in Amsterdam in March 2018.
However, England's run to the semi-finals of last year's World Cup passed off peacefully with far fewer fans travelling to Russia than are expected in Portugal over the next few days.