May Day 2012: The world celebrates

A boy dressed as Harry Potter holds a placard as protesters gather outside St Paul's Cathedral during the 'Occupy London' protest on October 15, 2011 in London, England.

May 1, or May Day, has long been celebrated around the world as International Worker's Day, or Labor Day. This year, the Occupy Wall Street movement joined labor groups for a day of protests to try to breathe fresh life into the movement that sparked a wave of nationwide protests against economic injustice eight months ago.

Here are some pictures of people around the world.