HONG KONG -- Demonstration sites at Mong Kok and Causeway Bay both saw escalating confrontations between supporters of the mass protest movement and anti-protest activists Friday evening. Police seemed unable to control the situation after a group of people decrying the demonstrations reportedly attacked protesters at the scene, while leaders of the Hong Kong Federation of Students suspended talks with the government in light of the violence.

“We’re very nervous,” said Markus Li, 21, who was at the Mong Kok protest site for several hours on Friday and said he saw opponents attacking members of the crowd. “They tried to harm us.”

Earlier in the afternoon, a small group of people who said they were nearby residents and business owners spoke out against the protests at Mong Kok, saying they were losing money thanks to the weeklong road blockade. But several demonstrators said their foes had been paid by the Chinese government to disrupt the movement.

By early evening, the anti-protest group had swelled and reportedly began hitting protest supporters in the crowd. By 7 p.m., however, the pro-Occupy crowd grew large enough to encircle its opponents in several pockets around the site along Nathan Road.

Demonstrators occasionally shouted, “Arrest them,” “Get out,” “Get off work,” or “Go back to China,” as police officers – who were few and far between – began escorting some of the anti-protest activists away. Many protest supporters kept their hands raised as a show of peace to prevent further violence.

While some critics of the protest have appeared at other demonstration sites around Hong Kong, witnesses said this was the first instance in which an anti-protest group appeared in one location en masse.

Unrest also escalated at Causeway Bay Friday night, where pro-Beijing supporters reportedly took down protest barricades.

“Hong Kong police need to protect the students,” said Winsome Chu, 27. Chu said she had seen an image circulating on Facebook depicting an advertisement recruiting people to join the anti-protest camp for pay.

Li said he thought Friday’s skirmishes and the ballooning anti-protest presence posed a threat to the student-led movement, “but I don’t think [the students] will be defeated that easily.”