Police use tear gas and water cannon as crowds defy Hong Kong rally ban

Police fired water cannon and tear gas at Hong Kongers who defied authorities with an illegal march on Sunday, their numbers swollen by anger over the recent stabbing and beating of two pro-democracy protesters.

Authorities had forbidden the march in Tsim Sha Tsui, a densely packed shopping district filled with luxury boutiques and hotels, citing public safety and previous violence from hardcore protesters.

But tens of thousands joined the unsanctioned rally regardless, as the movement tries to keep up pressure on the city's pro-Beijing leaders after nearly five months of protests and political unrest.

In a now-familiar pattern, the rally began peacefully but quickly descended into chaos as small groups of hardcore protesters hurled petrol bombs at a police station, subway entrances and at Chinese mainland bank branches.

Police responded with multiple volleys of tear gas. 

At one point a water cannon truck chased thousands of protesters down Nathan Road, one of the city's busiest shopping thoroughfares, leaving it streaked with blue-dye from the vehicle's turrets.

The dye, used to identify protesters, also contains a pepper solution which burns the skin on contact.

As the protesters fled the streets, front-liners stayed behind to slow the advance of riot police, setting fire to makeshift barricades. 

Tensions were running high after the leader of the group organising the weekend rally, Jimmy Sham, was hospitalised by men wielding hammers earlier in the week.

Then on Saturday night, a man handing out pro-democracy flyers was stabbed in the neck and stomach, reportedly by an assailant who later shouted pro-Beijing slogans. 

Many on Sunday's march said they wanted to show they were unbowed by the attacks and authorities increasingly banning public gatherings. 

"The more they suppress, the more we resist," a 69-year-old protester, who gave her surname as Yeung, told AFP. "Can police arrest us all, tens of thousands of people?"

Philip Tsoi, a self-described frontline protester, said they needed to keep getting numbers out even though many more hardcore activists like him had been "arrested or wounded" in recent weeks. 

"What I want is a truly democratic government whose leader is elected by Hong Kong people instead of selected by a Communist regime," he told AFP.