At least 10 people were injured after fireworks were shot from a moving car into a crowd of pro-democracy activists in Hong Kong.

Key points: It is still unknown who was responsible for the firework incident

It is still unknown who was responsible for the firework incident More than 40 people charged with rioting have appeared in court

More than 40 people charged with rioting have appeared in court This is the first time Hong Kong authorities have used rioting charges

The incident happened just before 3:00am as protesters gathered outside a police station in the district of Tin Shui Wai to demand the release of more protesters who were being held inside.

Videos posted on social media showed the fireworks apparently being fired towards the crowd from a car.

Activists ran for cover as the fireworks arced towards them.

It was not clear who was responsible, but tensions remain high in Hong Kong after weeks of anti-government protests.

Protesters and supporters are highly wary of being identified by authorities and suffering potential retribution at their places of work and study for their involvement.

At the Tin Shui Wai protest, volunteers handed out face masks and single-trip subway fare cards to prevent riders from being identified and their trips logged in a central database, while drivers who taped paper over their licence plates offered rides home.

Court imposes curfews

Clashes broke out on Tuesday night as hundreds of protesters gathered at the Kwai Chung police station. ( AP: Vincent Yu )

More than 40 people appeared in a Hong Kong court yesterday charged with rioting for their role in a recent protest that turned violent when thousands of activists clashed with police near Beijing's main representative office in the city.

Supporters rallied outside the court ahead of the group's appearance, standing in heavy rain and chanting "Reclaim Hong Kong, revolution of our times".

On Tuesday night, hundreds of protesters had gathered at the Kwai Chung police station where some of the activists were to be freed on bail.

Clashes broke out between the protesters and police, with one officer brandishing a gun to ward off the crowd.

A wave of protests that began in late April have plunged the former British colony into its biggest political crisis since its return to Chinese rule in 1997, but this is the first time authorities in the financial hub have resorted to using the rioting charge.

Under Hong Kong law, rioting is defined as an unlawful assembly of three or more people where any person "commits a breach of the peace", and a conviction can carry a 10-year prison sentence.

Most of the defendants were released on bail of $HK1,000 ($186). The court also imposed a curfew from midnight to 6:00am on most of them, and many were ordered to remain in Hong Kong.

The large demonstrations started last month as a movement against now-suspended extradition legislation, and have since grown to encompass broader demands around greater democracy and government accountability.

Police have been deploying an increasing range of crowd control measures, including tear gas, pepper spray, rubber bullets, shotgun beanbag rounds and sponge grenades fired from barrel-mounted grenade launchers.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 33 seconds 33 s Protesters storm Hong Kong's Kwai Chung police station

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