POLICE and protesters have clashed in Hong Kong as demonstrators tore up "smart" lamp posts equipped with cameras among increased surveillance fears.

Police used tear gas after some protesters threw molotov cocktails and bricks and others used an electric saw to cut through the bottom of a lamp post during an anti-government rally in Kowloon Bay on Saturday.

Video shows the angry protesters then stomped on the pole in scenes reminiscent of the fall of Saddam Hussein.

The financial centre has been racked by 12 weeks of protests sparked by a now-shelved extradition bill that would have seen suspects sent to mainland China.

The protest movement has grown to include other demands, such as for an independent inquiry into alleged police brutality.

The protesters, who were part of a larger group armed with bamboo poles and baseball bats, were marching to demand the removal of the lamp posts over concerns they could contain hi-tech cameras and facial recognition software used for surveillance by Chinese authorities.

Footage shared on social media captures the moment the pole topples over and black-clad demonstrators, holding up umbrellas and wearing masks to hide their faces, cheer as they watch it come crashing down.

The angry protesters can be seen stomping on the pole while others work to dismantle it believing it to be fitted with sensors, closed circuit cameras and data collecting networks.

The government in Hong Kong said smart lamp posts only collected data on traffic, weather and air quality.

About 50 of surveillance poles were installed in June, with 350 more set to be rolled out, Hong Kong Free Pressreports.

The protesters chanted slogans calling for the government to answer the movement's demands.

On Friday night, thousands of chanting protesters formed human chains around the city in a peaceful protest dubbed the "Hong Kong Way".

Organisers said 135,000 people took part in the demonstration, inspired by one in 1989 when an estimated two million people joined arms across three Baltic States in a protest against then-Soviet rule that became known as the "Baltic Way" or "Baltic Chain".

According to NBC NEWS, protesters formed a 28-mile human chain across 39 train stations in Hong Kong while singing songs and holding signs that read: "Thank you for supporting freedom and democracy."

The protest, which included people shining lights on sidewalks and atop Koloon's Lion Rock mountain, followed warnings from Beijing and city leader Carrie Lam to stop the demonstrations and restore order.

Authorities have so far refused to meet any of the protesters' five key demands, including calls for an independent inquiry into police brutality, a full withdrawal of the extradition bill, and full democracy.

Organisers are planning a host of protests in the coming weeks including a mass march, a citywide strike and class boycotts at universities.

With AAP