Police arrested key student leaders of Hong Kong's pro-democracy protests on Wednesday as they cleared barricades in one volatile district, throwing into doubt the future of a 2-month-old movement seeking free elections in the former British colony.

In the second day of the operation to clear one of three protest zones, police in helmets, some equipped with backpack pepper sprayers, swiftly removed metal barricades, tents, canopies and other obstructions in Mong Kok, a blue-collar neighborhood that has been the flash point of earlier clashes.

Local broadcaster RTHK said more than 20 people were arrested. Many other protesters scattered, but a handful faced off briefly against dozens of police on a side street, determined to await supporters that they expected to join them in the evening after getting off school or work.

Mong Kok has been home to a more raucous group of protesters than at the two other sites around the city. Previous efforts to clear the area have backfired, sending more people into the streets to confront police.

Police said a total of 116 were arrested during clashes the previous night that also left 20 officers hurt.

Among those arrested Wednesday were protest leaders Joshua Wong, the 18-year-old head of the Scholarism group, and Lester Shum, deputy secretary general of the Hong Kong Federation of Students.

"After the clearance operation we don't have a leader," said protester Ken Lee, 19, who quit his job at a restaurant in October after the protests erupted and spent his days in Mong Kok. "We need to wait until tonight, it all depends on what happens tonight, if the majority of the people want to reoccupy the area or go to another location."

The other remaining protest zones are across Victoria Harbor, including a sprawling main camp next to government headquarters on the edge of the financial district and a smaller one in the Causeway Bay shopping district.

The protesters are demanding that Hong Kong's government scrap a plan mandated by China's Communist leaders to use a panel of Beijing-friendly elites to screen candidates for top leader in inaugural 2017 elections. The arrest of the student leaders could reinvigorate the protest movement, which has been losing steam as the Hong Kong government's apparent strategy of waiting out the protesters left them with few options.

Organizers estimated that as many as 200,000 people took to the semiautonomous Chinese city's streets at the start of the protests, but numbers have since dwindled sharply, along with public support.

In the latest push, police were acting to enforce the court injunction granted to taxi drivers to remove obstructions along Mong Kok's Nathan Road. Cleanup crews piled up junk left behind by the protesters and the road gradually opened up to traffic and pedestrians later Wednesday.