Hundreds of thousands of people dancing and wearing costumes are packing the streets of South America's biggest city to celebrate gay pride and call for an end to homophobia.

Gays, lesbians and their supporters in Sao Paulo, Brazil, are participating in the city's 15th annual gay pride parade on skyscraper-lined Avenida Paulista. Many are dancing to the beat of loud music blasting from several sound trucks.

Organizers hope more than 3 million join in the parade, which they say is one of the biggest in the world. Police have not given an estimate of how many people are parading.

Police have reported a few arrests for drug possession but say no major incidents have occurred.