A 38 year-old man was assaulted in Malmö, Sweden, on Sunday - for the sole crime of hanging an Israeli flag in his window.
The assailants broke the man's window first, prompting him to seek the perpetrators, police said.
"After that the man went out onto the street to see what was going on. Then he was attacked and it was on the basis of the flag. That is the information we have at present," police told the TT news agency Monday.
They added that ten people chased the man from his building, wielding iron pipes. He managed to narrowly escape his attackers and was taken to hospital with serious injuries.
"Our initial evaluation is that this is a hate crime," Malmö policewoman Marie Keismar added. The incident has been categorized as "aggravated assault."
Sketches of the perpetrators have been distributed across Malmö, according to the Sydsvenskan newspaper.
Malmö has been a frequent flashpoint for anti-Semitism in Europe over the past year.
Irish journalist Patrick Reilly made headlines in 2013 when he donned a yarmulke for a day in the southern Swedish city to test what it felt like to be a Jew there, and reported that the experience was "terrifying."
As quoted in an article by Swedish news source The Local, Reilly stated that his fear escalated with each passing minute.
"Whether the threat was real or imagined the fear was genuine and that stemmed from what I was wearing on my head," he noted. "As an Irish person abroad I've never felt remotely threatened but wearing the kippah for a few hours was enough to instill feelings of fear."
"Even when I didn't feel afraid I was made to feel different and unwelcome."
Several months later, Malmö made headlines again, after Jewish rights advocate and Swedish citizen Annika Hernroth-Rothstein applied for asylum in her own country. She singled out the city for scrutiny.
"According to The Swedish National Council for Crime Prevention, anti-Semitic crimes have tripled since 2010," Hernroth-Rothstein wrote at the time.
"Worst is the situation in Malmö where we see an increase in 320% just from the year 2011. These are the statistics of reported crimes; we can only imagine how many crimes go unreported each year."