AP Photo/Jorge Saenz
Paraguayan workers, some members of "Corriente Clasista y Combativa," a workers union, shout slogans during May Day celebrations in Asuncion, Thursday, May 1, 2008. Workers demanded more jobs and better salaries.
Cuba
AP Photo/Javier Galeano
Students hold a banner of Cuba's Fidel Castro during a May Day parade at the Plaza of Revolution in Havana, Thursday, May 1, 2008.
AP Photo/Javier Galeano
A man carries a monkey holding a Cuban flag during the May Day parade at the Revolution Square in Havana, Thursday, May 1, 2008.
AP Photo/Sven Creutzmann, Pool
Cuba's President Raul Castro waves to demonstrators during the International Workers Day parade at the Revolution Square in Havana, Thursday, May 1, 2008.
Switzerland
CBS
A protester blows soap bubbles towards Swiss policemen during a peaceful demonstration on Labor Day, in Zurich, Switzerland, Thursday, May 1, 2008.
AP/Keystone/Steffen Schmidt
Protesters throw stones during clashes with police during the Labor Day protests in Zurich, Switzerland, Thursday May 1, 2008.
Germany
AP Photo/Fabian Bimmer
A demonstrator is seen as Police use water cannons during May Day clashes in Hamburg, Germany on Thursday, May 1, 2008.
AP Photo/Fabian Bimmer
A car burns during May Day clashes in Hamburg, Germany, on Thursday, May 1, 2008.
Russia
AP Photo/Dmitry Lovetsky
Young supporters of the Communist party march to mark the May Day holiday in St. Petersburg, Russia, Thursday, May 1, 2008. Thousands of Communists, members of Russia's main political parties and opposition activists staged competing marches in Moscow and other cities Thursday marking the traditional holiday.
Romania
AP Photo/Vadim Ghirda
Romanian Roma children watch a small May Day parade in Bucharest, Romania, Thursday, May 1, 2008. (AP Photo/Vadim Ghirda)
Serbia
AP Photo/Dark Vojinovic
Serbian workers march with a banner, reading: "Say no to both EU and NATO and to Russia," during a May Day rally in Belgrade, Serbia, Thursday, May 1, 2008. Dozens of workers jeered Serbian President Boris Tadic during the protest in the capital. Tadic attended the May Day rally at a central Belgrade square to express support for the workers' demands.
Turkey
AP Photo/Ibrahim Usta
Workers chant slogans from a building during a Labor Day demonstration in Istanbul, Turkey, Thursday, May 1, 2008. Turkish riot police used clubs, tear gas and water cannons to break up crowds of workers and students trying to reach a main Istanbul square for a Labor Day rally banned by the government. Authorities said 505 demonstrators were detained and six police officers were injured.
AP Photo/Murad Sezer
A young Turkish woman runs to avoid tear gas in Istanbul, Turkey, Thursday, May 1, 2008.
Sri Lanka
AP Photo/Eranga Jayawardena
A Sri Lankan boy waves a flag during a May Day rally of the local Marxist party, People's Liberation Front in Colombo, Sri Lanka, Thursday, May 1, 2008.
Greece
AP Photo/Thanassis Stavrakis
A protester seen through red flags shouts slogans as he marches in central Athens on Thursday, May 1, 2008. About 5,000 protesters took part in two separate marches in the Greek capital to mark the May Day labor holiday. Labor unions are at odds with Greece's conservative government over planned pension reforms which they argue will reduce benefits for most pensioners.
Philippines
AP Photo/Bullit Marquez
A police officer walks past rows of riot shields as thousands of protesters hold a rally at the foot of Mendiola Bridge near the Presidential Palace to mark Labor Day Thursday May 1, 2008, in Manila, Philippines. The protesters denounced a non-wage package announced by the government and are demanding an across-the board wage increase they claim is still not enough to offset spiraling food and fuel price increases.
Pakistan
AP Photo/Shakil Adil
A Pakistani woman working at a fishery chants slogans behind a fishing net during a rally during a May Day observance in Karachi, Pakistan, Thursday, May 1, 2008.
San Francisco
AP Photo/Paul Sakuma
Members of the Exotic Dancers Union 1021 march during a May Day rally in San Francisco, Thursday, May 1, 2008. Thousands of union supporters participated in the rally.