Opposition leaders Mir-Hussein Moussavi, Mehdi Karroubi, and Muhammad Khatami joined the crowds, drawing appreciative cheers and chants from supporters. Here, a government supporter tries to accost Mr. Moussavi, who has a gray beard and glasses.

Photo: Associated Press

Conservatives had warned against using the annual pro-Palestinian march as an excuse for renewed protests against President Mahmoud Ahmadinejad, whose disputed re-election in June plunged Iran into its worst internal crisis in three decades. But the protesters turned out anyway, often walking alongside larger groups of state-sanctioned marchers.

Photo: Newsha Tavakolian/Polaris, for The New York Times