HONG KONG — Hundreds of thousands of protesters, basking in a recent election victory by Hong Kong’s pro-democracy camp, poured onto the city’s streets on Sunday in one of the largest marches in weeks to pressure the government to meet demands for greater civil liberties.

The huge turnout was a reminder to China’s leader, Xi Jinping, that the monthslong campaign against his authoritarian policies still had broad support in Hong Kong despite a weakening economy and increasingly violent clashes between protesters and the police.

Tensions in Hong Kong, a semiautonomous territory, had eased somewhat in recent days, after pro-democracy advocates won a stunning victory in local elections two weeks ago, giving new hope to the movement.