HONG KONG — Hong Kong police cleared more barricades Tuesday from pro-democracy protest zones that have choked off traffic in key business districts for more than two weeks, signaling authorities’ growing impatience with the student-led activists.

Appearing to use a strategy of gradually chipping away at the three main protest zones, hundreds of police fanned out in the early hours to take down barriers that the protesters had erected overnight. Officers used electric saws and bolt cutters to take down bamboo scaffolding built in the Admiralty area after a mob of masked men stormed some of the barricades the day before.

A few dozen protesters who sat guarding one entrance to the main occupied zone after the police came were exhausted but defiant.

“I’m feeling a bit lost. There is no dialogue with the government, and the truth is we are affecting people’s lives. But we can’t bear to leave without getting any results,” said Mark Li, a 21-year-old college student who sat at the front facing a line of policemen.