Black-clad student demonstrators have been making a concerted effort to defend their campuses against what they see as unwarranted police encroachment.

On Tuesday, protesters at the Chinese University of Hong Kong built roadblocks outside an entrance while police officers elsewhere tackled demonstrators to the ground and fired tear gas at a group gathered on a sports field.

As the clashes escalated in the evening, the university’s vice chancellor, Rocky Tuan, met with students in hopes of brokering a cease-fire between protesters and the police.

“The deal is that we each need to take a step back,” he said as he urged the students not to escalate the confrontation. In response, the students shouted: “We don’t believe you!” They repeatedly interrupted him and called for the release of students who had been arrested.