In this image taken on Tuesday, Nov. 16, 2010 Muslim immigrants hold outdoor prayers for the festival of Eid-al-Adha, outside Athens University, in central Athens . Human rights and immigrant groups have warned of a sharp rise in anti-immigrant attacks in Athens in recent months, carried out by far-right groups. In Greece, alarm is rising that the twin crises of financial meltdown and continent-leading illegal immigration are creating the conditions for a right-wing rise and the Norway massacre on Monday Aug. 1, 2011 drove authorities to beef up security measures. (AP Photo/Thanassis Stavrakis)