Hong Kong Police Fire Blue Dye In Water Cannons, Storm Subway With Batons

Protesters in Hong Kong threw petrol bombs at government headquarters and set fires in the streets, while police stormed an underground rail carriage and hit passengers with batons and pepper spray.

The scenes on Saturday seem certain to further inflame tensions in a city riven by nearly three months of pro-democracy demonstrations.

Police had denied permission for a march to mark the fifth anniversary of a decision by China against fully democratic elections in Hong Kong, but protesters took to the streets anyway, as they have all northern summer.

They provoked and obstructed police repeatedly but generally retreated once riot officers moved in, avoiding some of the direct clashes that characterised earlier protests.

Late at night, though, video from Hong Kong broadcaster TVB showed police using batons while on the platform of Prince Edward station and swinging batons at passengers who backed into one end of a train car behind umbrellas.

Protestors face off against police in Hong Kong on Saturday. Photo: AAP

The video also shows pepper spray being shot through an open door at a group seated on the floor while one man holds up his hands.

It wasn't clear if all the passengers were protesters. Police said they entered the station to arrest offenders after protesters assaulted others and damaged property inside.

The TVB video was widely shared on social media as another example of police brutality during the protests.

Angry crowds gathered outside Prince Edward and nearby Mongkok station, where police said they made arrests after protesters vandalised the customer service centre and damaged ticket machines.

READ MORE: Hong Kong Fire Tear Gas At Protesters

Protests erupted in early June in Hong Kong, a semi-autonomous Chinese territory of 7.4 million people. A now-shelved China extradition bill brought to the fore simmering concerns about what many in the city see as an erosion of the rights and freedoms that residents are supposed to have under a "one country, two systems" framework.

The mostly young, black-shirted protesters took over roads and major intersections in shopping districts on Saturday as they rallied and marched with no obvious destination in mind.

Authorities closed streets and a subway stop near the Chinese government office and parked water cannon trucks and erected additional barriers nearby, fearing protesters might target the building. The office would have been the endpoint of the march that police did not allow.

Police fire blue-colored water from water cannons at protestors in Hong Kong, Photo: AAP

Instead, a group of hard-line protesters decided to take on police guarding government headquarters from behind large barriers that ring the building to keep demonstrators at bay.

While others marched back and forth nearby, a large crowd wearing helmets and gas masks gathered outside. They pointed laser beams at the officers' heads and threw objects over the barriers and at them. Police responded with tear gas, and protesters threw gasoline bombs into the compound.

Hong Kong Police Storm Subway With Batons

Then came the blue water. A water cannon truck fired regular water, followed by repeated bursts of coloured water, staining protesters and nearby journalists and leaving blue puddles in the street.

READ MORE: Why Are Protests In Hong Kong Still Going Strong? 

The standoff continued for some time, but protesters started moving back as word spread that police were headed in their direction. A few front-line protesters hurled gasoline bombs at the officers in formation, but there were no major clashes as police cleared the area.

Protesters regrouped and blocked a major commercial street by piling up barricades and setting a large fire. Smoke billowed into the air as hundreds of protesters waited on the other side of the makeshift barrier, many pointing laser beams that streaked the night sky above them.

Firefighters made their way into the congested area on foot to put out the fire. Police in riot gear removed the barricades and moved in quickly. They could be seen detaining a few protesters, but by then, most had already left.

Protesters face police on a street. Photo: AAP

As police advanced east down Hennessey Road, protesters made another stand in the Causeway Bay shopping district. They threw gasoline bombs at police, who fired tear gas and water cannons.

Protesters built another fire, a smaller one, in front of Sogo department store. Police waited behind their riot shields while firefighters put out the smouldering fire with extinguishers. When police moved in, the protesters had again retreated.

Other groups crossed Hong Kong's harbor to the Tsim Sha Tsui district, where police said they set fires and threw petrol bombs on Nathan Road.