On New Years Eve in the small town of Ełk in Northwestern Poland (60,000 inhabitants) a 21 year old young man named Daniel, who’d been questioned by police four times in 2016 for petty crimes, tried to steal a couple of drinks from a kebab restaurant in the center of town possibly after an altercation with the employees. When he was unsuccessful he (or a friend) threw a firework into the establishment (or the two happened at the same time, reports vary). The owner and three employees (from Algeria, Morocco and Tunisia) chased him down and physically attacked him and by the time it was over Daniel had been stabbed twice and died.
The next day some people wanted to leave candles in front of the restaurant and a larger number (maybe 300) began disturbances and throwing large stones through the windows and generally demolishing the restaurant (later another restaurant owned by the same person, from Algeria, was attacked as was the apartment he was renting).
The lesson is that loutish young men do loutish things.
Police showed up and a total of 28 people have been taken into custody and one of the employees of the restaurant (from Tunisia) has been charged with murder. Later the owner was also charged.
This is getting lots of coverage in the Polish media and may or may not go international. But I don’t think examining it in closer detail will reveal anything very productive about much of anything beyond the perils of hotheaded young men, regardless of culture, engaging in lunkheaded violence.