Greece, struggling to exit its worst financial crisis in decades, has become a frontier for immigrants mainly from Asia and Africa, who seek a better life in Europe but often end up living in cramped detention centres.
More than 50 out of 1,620 migrants held at the detention centre of Amygdaleza, near Athens, were arrested over the clashes, which broke out late on Saturday.
The detainees hurled water bottles and stones at guards and set garbage bags and mattresses on fire, injuring 10 police guards. There were no reports of injured migrants, police said.
Riot police fired teargas to disperse the crowds, ending the unrest. Police said 10 migrants had escaped.
Greece has been long criticized by human rights groups over the poor conditions at reception centres and a very low rate of asylum application approvals, which makes its treatment of illegal migrants one of the toughest in the EU.
Since the economic crisis broke out, anti-foreigner sentiment has risen in a country where one worker in four is unemployed, boosting the far-right Golden Dawn party which has been ranking third in polls.
