Discussions between the protesters and the government broke down after the violence. With thousands of protesters still in the streets, some are fearing that a crackdown might be imminent.
In the territory's crowded Mong Kok district, a group of anti-Occupy Central demonstrators broke through police lines and tore up the pro-democracy activists' camp.
Leung Chun-ying told reporters that he appointed his deputy to meet with student activists to discuss "constitutional development," but he renewed warnings about occupying government buildings.
Hong Kong media are providing wall-to-wall coverage of the protests calling for the resignation of Chief Executive Leung Chun-ying, but in mainland China there has been little mention of the unrest.