Chinese state media have ramped up the rhetoric against Hong Kong's pro-democracy campaigners, describing them on Tuesday as "mobsters", warning they must never be appeased and raising the spectre of mainland security forces intervening to quash them.

China warned Hong Kong protesters Tuesday that "those who play with fire will perish by it", adding the immense strength of the central government should not be underestimated.

Pro-democracy protesters in Hong Kong are set to defy Chinese authorities with another two major rallies later Sunday, a day after police fired tear gas to disperse them in one of the city's most renowned tourist districts.

Hundreds of Hong Kong protesters, including flight attendants, held a rally in the airport's arrival hall on Friday in a bid to "educate" visitors about the unprecedented demonstrations currently roiling the international finance hub.

Tens of thousands of people rallied in support of Hong Kong's police and pro-Beijing leadership on Saturday, a vivid illustration of the polarisation coursing through the city after weeks of anti-government demonstrations.

A peculiar legacy of Hong Kong's colonial past has emerged as a focal point of rage for anti-government protesters: a dwindling band of expat police officers now vilified for doing the bidding of the city's pro-Beijing leaders.

Hong Kong's 32,000-strong police force have found themselves fighting unprecedented running battles with protesters for the past five weeks following a huge backlash to a now-suspended plan to allow extraditions to the Chinese mainland.

Clashes broke out between police and Hong Kong demonstrators on Saturday as the latest anti-government protests took aim at traders coming across the border from mainland China.

Hong Kong leader Carrie Lam said Tuesday that the effort to amend a highly contentious extradition bill was dead, but it wasn't clear if the legislation was being formally withdrawn as protesters have demanded. Leaders of the monthlong protest movement vowed to keep up pressure until the legislation is officially revoked.

Lam acknowledged at a news conference that there were "lingering doubts about the government's sincerity or worries whether the government will restart the process in the Legislative Council." But she said: "I reiterate here, there is no such plan. The bill is dead."

Five people were arrested during overnight clashes in Hong Kong between riot officers and anti-government protesters, police said Monday, as the political violence rocking the international hub shows no sign of abating.

A Hong Kong street artist was charged on Friday with assaulting a police officer and criminal damage, the first prosecution against an anti-government protester since the city was rocked by unprecedented demonstrations.