On Monday, groups of men, some of them wearing masks, tried to remove barricades erected by Hong Kong’s demonstrators to block off main roads near the heart of the city’s financial center. Some members of the crowd chanted “Open the road!”

Police struggled to keep the two groups apart as they faced off across the barricades in the Admiralty district.

The city’s pro-democracy protesters said last week that they had come under attack from organized crime gangs known as triads, alleging that police did not do enough to intervene. Amnesty International was similarly critical in this regard in a statement issued on Friday.

Many in Hong Kong do not support the ongoing protests demanding that the Chinese central government grant Hong Kong, a partly autonomous region, full democracy. This includes the city’s taxi drivers, whose business has been seriously affected by the protests.

Earlier on Monday, the Hong Kong police began removing barricades from the camp sites of pro-democracy protesters, who have vowed to block the financial hub’s main roads until the central government in Beijing removes restrictions on the city’s next election. Residents of Hong Kong will elect a successor to Chief Executive Leung Chun-ying in 2017, but Beijing announced in August that only vetted candidates will be allowed to stand for the post.