Earlier in the day, Keith Fong, the leader of the Baptist University student union, was arrested over suspicion of possessing weapons as police found ten laser pointers on him.
More than a hundred people encircled the Sham Shui Po police station to demand his release, and police fired several rounds of tear gas to disperse them, the RTHK broadcaster reported.
A rally also swept Hong Kong on Monday as thousands of protesters almost completely blocked the city's traffic and engaged in violent clashes with law enforcement. Police had to use tear gas and rubber bullets to disperse demonstrators. As many as 148 people were detained on charges of unlawful assembly, riot, assault of police officers and possession of weapons.
Hong Kong is in its third month of public unrest. People took to the streets in early June to protest against the adoption of a bill that would allow Hong Kong to extradite suspects to jurisdictions with which it did not previously have an extradition agreement, including mainland China. Even though the government announced it was suspending the bill, people are demanding that it be withdrawn completely.