Groups of right-wing extremists chased and attacked immigrants through the streets of Athens Thursday during a protest against a deadly mugging of a Greek man earlier this week, DPA reported.
Nationalists and far-right groups have blamed immigrants for Tuesday's stabbing of a Greek man in an area of the city where many immigrants are known to live, although officials say no evidence has been revealed to suggest that they are responsible.
The murder has shocked and sparked outrage, as the victim had been about to drive his pregnant wife to a maternity hospital and was apparently killed for his video camera.
More than 2,000 hooded youths, carrying sticks and broken bottles, could be seen chasing and clashing with immigrants through the streets in central Athens, sending others to run for cover during the rally.
Riot police fired several rounds of tear gas to disperse the crowd. At least 15 immigrants and one Greek man were hospitalised with injuries while more than 50 people were reportedly detained.
Similar anti-immigrant rallies have taken place since Tuesday night, after the fatal stabbing.
Police are also investigating the fatal stabbing of a 21-year-old Bangladeshi, which took place earlier Thursday in central Athens. No arrests have been made and the motive for the attack remained unclear.
"There is the serious threat of Athens becoming a war zone similar to the likes of Beirut during the 1970s," said Athens Mayor Giorgos Kaminis.
Immigrants have been beaten and stabbed in many of the city's squares over recent months. Several makeshift mosques, usually situated in garages or basements of apartment blocks, have been bombed, set on fire, and vandalized.
Last year, assailants locked the door of a basement prayer house and hurled firebombs through the windows, seriously wounding five worshippers in the area of St Panteleimonos.
The area is often the site of angry rallies by local residents, often infiltrated by extreme nationalist groups. The anger is aimed at what they charge is a crime wave fuelled by illegal immigrants and the downgrading of the neighborhood.
Far-right groups have won increasing public support in recent months. The leader of group Chrysi Avghi won a seat on Athens' city council for the first time in elections last November.