A small but determined group of protesters remained holed up inside a Hong Kong university campus as the city’s largest pro-Beijing political party urged voters to “kick out the black force” in upcoming elections seen as a key gauge of public support for anti-government protests.

At least a few dozen protesters at the Hong Kong Polytechnic University, that has been ringed by police for days, resisted pleas to surrender amid fears of being arrested.

They come from a much larger group that occupied the campus after battling police over the weekend.

Some 1,000 protesters have either surrendered or been stopped while trying to flee.

Hong Kong Protests
Starry Lee Wai-king, centre, chair of pro-Beijing party Democratic Alliance for Betterment of Hong Kong (DAB) and their supporters attend an election campaign event (Kin Cheung/AP)

The city’s largest political party slammed the flare-up in violence in the past week and urged some 4.1 million voters to use the ballot box this Sunday to reject the “black force” that had thrown the semi-autonomous Chinese territory into unprecedented turmoil since June.

“The black force say they want to fight for freedom but now people cannot even express their views freely. We have even been stripped of our right to go to school and work,” said Starry Lee, who heads the Democratic Alliance For The Betterment And Progress Of Hong Kong.

The party is contesting 181 of the 452 district council seats, a low-level neighbourhood election held every four years.

For the first time ever, all the seats will be contested and a huge win by the pro-democracy bloc could bolster the legitimacy of the protest movement.

Protesters, who believe China is increasing control over the semi-autonomous territory, are demanding fully democratic elections and an independent probe into alleged police brutality against demonstrators.

Hong Kong Protests
People hold up their hands to represent the five demands of the protests (Ng Han Guan/AP)

The government, which rejected the demands, has warned the polls could be delayed if violence persists and transport links are disrupted.

Earlier Thursday, there were long lines and delays at some underground stations as some stations remained shut and some protesters tried to block train doors from closing but the disruption was relatively minor.

Lee said the party’s candidates have faced threats and some have even been beaten up but they are ready for a “tough battle“ for Hong Kong.

“We believe that if we are united and if everyone comes out to vote, Hong Kong can be restored and violence can be stopped,” she said at a campaign event in a park downtown with dozens of the party’s candidates.

Hong Kong Protests
Staff of the Hong Kong Polytechnic University inspect the damage (VIncent Thian/AP)

Lee and some candidates kicked black footballs as a symbolic gesture to banish the black-clad protesters.

More than 5,000 have been arrested since the protests started in June over a now-abandoned extradition bill that would have allowed criminal suspects to be sent to mainland China for trial.

The protest has since swelled into an anti-China movement as many fear a loss of freedoms guaranteed to the former British colony when it returned to Chinese control in 1997.

Pressure ratcheted up on Hong Kong as the US Congress approved legislation late on Wednesday to sanction officials who carry out human rights abuses and require an annual review of the favourable trade status that Washington grants Hong Kong.

Hong Kong Protests
A protester is wheeled on a stretcher by first aid personnel (VIncent Thian/AP)

Another bill bans export of tear gas and other non-lethal tools to Hong Kong.

President Donald Trump is expected to sign the bills into law, which is sure to anger China and jeopardise trade talks between the two economic giants.

Hong Kong’s financial secretary Paul Chan said Thursday that the US legislation was baseless and an unnecessary meddling into the city’s affairs.

He urged Washington to reconsider, warning it would also hurt the interest of more than 1,000 American businesses in Asia’s top financial hub.