Violence erupts hours before England's clash with Serbia: Three Lions fans left bloodied as they skirmish with hooligans in German city

Clashes are breaking out between England and Serbia fans in Germany ahead of the teams' opening match of the Euros later today. 

Riot police have clashed with supporters outside a bar in Gelsenkirchen as violence boiled over for the first time this afternoon.

Officers moved in after trouble erupted between fans outside a restaurant just after 3.30pm. It is thought Albanian fans may have launched the initial attack against arch-rivals Serbia, with some England fans becoming caught up in the violence.

It comes ahead of the teams' tie set to kick off at 8pm tonight in the first match of the group stages of the European Championships. 

Tables, chairs and bottles appeared to have been hurled between two groups of fans.

It was not immediately clear what sparked the disorder but one man - believed to be English - was seen being led away with blood streaming down his face.

Witnesses reported a 'masked' group of men suddenly burst around a corner and began throwing bottles. 

An eyewitness told MailOnline: 'There was a sudden burst of violence. It came out of nowhere.

'It was unclear who started what. But to me it seemed liked a group of England fans rushed the bar where Serbs were drinking and it all kicked off with tables, chairs and bottles thrown.

'One man had blood pouring from a head wound - he was English I believe.'

In videos on social media, glass could be heard being smashed as police ran down a street in the centre of town. 

One clip showed several dozen fans throwing restaurant chairs and tables at one another before one group fled with the other giving chase.

Police officers joined the chase and broke up altercations which left several fans with blood pouring from their faces.

One fan could be seen curled up on the ground, bring kicked by rivals before police intervened. 

Riot police descended on the scene within minutes of the violence and forced those still in the vicinity inside the steakhouse. Officers then quickly surrounded the terraced property with police vans blocking each end of the street.

An Englishman, who would only give his first name, Larry, and who had been drinking with the Serbs when the attack was launched, said a group of men in balaclavas 'ran around the corner and started throwing bottles.'

He added: 'I ran away and the next thing I saw was the tables being smashed and chairs being thrown'.

His friend, another Englishman living in Belgrade who did not want to be named, added: 'It was premeditated. They threw bottles, I just ran off.'

A mother and son enjoying their regular Sunday routine of coffee and cake at the Café Pabot opposite the Hirt Steakhouse said they were sat on the first floor when 'all of a sudden bits of food and bottles started being thrown.'

The son, Felix Wurmes, 35, added: 'It happened so fast. Then one group ran off, followed by the other.'

His mother, Beate Rafrlkski, 66, added: 'They have had too much beer I expect – there's too much emotion. We were anxious the trouble was going to spread to inside the café.'

Café worker Petra Thiel said another person who was in the café at the time told her she had heard the attackers shouting something in Serbian.

'In total, there were about 50 people involved', she added. 'I didn't see any maskes'.

England fan Matthew Simpson had been socialising with the Serbian group moments before the trouble erupted. He said he was told the attackers had been Albanians.

There have been united calls for peace amid fears that hooligan clashes could overshadow the match - as Serbian thugs appeared to display online St George's cross flags 'stolen' from English travelling groups.

Football fans in Serbia have a track record of serious violence - with hooligan groups linked to organised crime groups accused of kidnap, rape and even murder.

Red Star Belgrade ultras, known as the Delije or 'Strong Boys', they are said to specialise in gang warfare, political violence, racketeering and organised crime. 

The Balkan country's most notorious hooligan, Ivan Bogdanov, is a fearsome figure known as 'Ivan the Terrible' who has spent more than two years in Italian and Serbian jails. 

An estimated 40,000 England supporters are believed to have descended this weekend on Gelsenkirchen and neighbouring cities such as Dusseldorf and Cologne.

German police have been working with authorities from London and Belgrade to try to avoid ugly scenes in the areas around the stadium and during the game itself.

Tonight's game marks a return to Gelsenkirchen 18 years after Wayne Rooney saw red there as England crashed out of the World Cup yet again on penalties.

England manager Gareth Southgate has encouraged supporters to enjoy their time in Germany.

Yet local police have labelled tonight's game 'high risk' following reports earlier last week of Serbian ultras making their way to the region.

Serbia's football fans are well known for hooliganism, with some groups being linked to the far-right.