Photos: May Day protests around the world

A demonstrator is arrested during May Day protests demanding everything from wage increases to an end to austerity measures Tuesday, May 1, 2012 in Oakland, Calif. Crowds had blocked intersections in the city and tried to force businesses to shut down for not observing calls for a "general strike." The city has been the scene of some of the fiercest clashes between police and Occupy protesters in recent months. (AP Photo/Marcio Jose Sanchez)