MOSCOW — Russia celebrated May Day with its first joyful parade across Red Square since the Soviet Union collapsed in 1991, as President Vladimir Putin basked in a surge of patriotism over Crimea’s annexation. In Turkey, scores were injured in clashes with police.

Elsewhere in the world, demonstrators turned out Thursday to press their demands for better treatment on the holiday also known as International Workers’ Day. A rally also turned violent in Cambodia’s capital. Relatively few mark May Day in the United States, although hundreds gathered Thursday in Los Angeles, chanting for immigration and human rights reform.

Security forces in Istanbul’s iconic Taksim Square pushed back International Workers’ Day demonstrators with water cannons and tear gas. Protesters retaliated by throwing objects at police and using slingshots. Police said 142 people were detained and 90 were injured, 19 of them police officers.

The Moscow parade of about 100,000 people was organized by trade unions and ostensibly dedicated to honoring the working class. The overarching theme, however, was Russian pride over last month’s annexation of Crimea. Putin, who did not attend, was saluted as a national hero.

A long stream of marchers held up signs saying “I’m proud of my country,” “Let’s go to Crimea for vacation” and “Putin is right.” Russian flags fluttered through the crowd.

Putin further tapped into nostalgia for the Soviet Union by handing out “Hero of Labor” awards during a Kremlin ceremony after the march. The awards, which were created under dictator Josef Stalin and disappeared along with the Soviet Union, were reinstated last year.

May Day also was celebrated with huge organized marches in Cuba, where thousands filed through Havana’s Revolution Plaza on Thursday to a soundtrack of congas, drums and cries of “Long live the revolution!”

Doctors in white smocks, uniformed government employees and construction workers waved Cuban flags and banners honoring Fidel and Raul Castro, guerrilla leader Ernesto “Che” Guevara and late Venezuelan President Hugo Chavez.

In Greece, more than 15,000 people attended peaceful rallies in central Athens to protest austerity measures in the crisis-hit country. In Cambodia, civilian auxiliary police armed with clubs turned on demonstrators after opposition leaders spoke to a crowd of nearly 1,000 in Phnom Penh. The assaults appeared to be random and limited, and were over in less than an hour. At least five people were hurt.