Albania fans had been in the area in the aftermath of their country’s 2-1 loss to Italy in nearby Dortmund their first group stage game last night – while Serbian supporters were having lunch ahead of their own opener against Gareth Southgate’s England side tonight.

And the clashes follow the news that England fans feeling threatened by Serbian “hooligans” during the two countries’ opening game have been handed a secret ‘code word’ to flag down fears to police and match staff.

The Three Lions faithful at England vs Serbia can ask German authorities overseeing the tournament “Wo geht’s nach PANAMA? [Which way to PANAMA?]” if crowd troubles begin to stir, the Telegraph revealed just days ago.

And this isn’t the only time today that German police have been called into action; mere hours earlier, armed officers descended on streets outside a fan zone in fellow host city Hamburg after an axe-wielding man began threatening football supporters ahead of a Netherlands vs Poland game.

The attacker, wielding a pickaxe and a “Molotov cocktail”-style incendiary device, also threatened officers as they policed fans on the Reeperbahn, a major road in Hamburg’s St Pauli district.

Officers had begun to use pepper spray against the axeman before opting to use their weapons, German outlet Bild reported.

And police said that one officer initially fired a warning shot to stop the attacker – before several more rounds were let off until the man finally fell to the ground.

Additional footage from the scene shows the attacker apparently attempting to light the “Molotov cocktail” before police shot him.

One witness at the scene, a Dutch football fan, praised the police response, saying officers “acted sharply and quickly”.