In this image taken Tuesday, Nov. 16, 2010 riot police look on a residents protest against Muslim immigrants holding outdoor prayers nearby, in this picture taken in central Athens on . 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)