Hong Kong has been the set of pro-democracy protests for several weeks, but the activist march that started peacefully last night ended in unprecedented violence. Police fired tear gas and shot rubber bullets at protesters and later on, masked thugs attacked demonstrators and commuters at a train station.

Dozens of masked men wearing white shirts stormed a transit station in Yuen Long last night and beat people with wooden rods and pipes. 45 were injured and sent to the hospital, with one currently in critical condition.

Footage taken by protesters and other commuters captured the attack’s startling brutality.

While it is not known exactly who organized the attack, it was believed to be orchestrated by organized crime syndicates. Some think the police, who arrived after the attack, and the current pro-Beijing government, are encouraging the behavior, reported The Guardian.

The violence was precipitated by a series of mass protests in recent weeks, surrounding an extradition deal with China that would compromise Hong Kong’s independence. This issue has proven to be a catalyst for broader demands for democratic reform, and incredibly divisive between pro-democracy and pro-Beijing citizens.