Police in Hong Kong have used tear gas for the first time in about 10 days to try to break up fresh anti-government protests.

The latest demonstrations took place in the Kwun Tong industrial district of the city.

Protesters took to the streets to demand the removal of smart lampposts over fears they could contain high-tech cameras and facial recognition software used for surveillance by Chinese authorities.

Activists, carrying umbrellas in the sweltering heat, filled a main road in the Kowloon peninsula, calling for the government to answer their demands.

Some protesters set up makeshift barricades on a road outside a police station, as they faced off with police in riot gear.

Demonstrators wield umbrellas and bamboo poles during a protest in Hong Kong | Image: Vincent Yu/AP/Press Association Images

"Hong Kong people's private information is already being extradited to China. We have to be very concerned," said march organiser Ventus Lau.

Umbrellas have become a symbol of passive resistance against the authorities.

The Umbrella Movement is a political group which emerged during the Hong Kong democracy protests of 2014.

The latest wave of demonstrations began almost three months ago over a now-suspended bill which would allow criminal suspects in Hong Kong to be extradited to mainland China.

The protests are also fuelled by concerns about the erosion of freedoms guaranteed under the "one country, two systems" formula that was put in place after the territory returned to Chinese rule in 1997.