Riot police fired tear gas and pepper spray on Nathan Road on Saturday evening after about 100 protesters gathered to block the major thoroughfare, marking six months since major clashes on August 31.

One officer was seen on a live stream drawing his gun during the exchanges.

Police had arrived at 8pm and used the non-lethal weapons to disperse the crowds and clear the roadblock near Prince Edward railway station, firing about 10 rounds of tear gas. A fire was set on the road, but firefighters soon put it out.

Some reporters, standing among the protesters, were pepper-sprayed as police dispersed the crowds. Two people required medical assistance and left the scene by ambulance. At least one man was subdued by police.

By about 8.30pm, protesters had not left the scene, and some were still building barriers with rubbish bins in the road.

And shortly before 11pm, a live news stream online showed a policeman drawing his pistol and pointing it at protesters on Soy Street, Mong Kok, after he had objects hurled at him. He appeared to have injured his right elbow, and urged the crowds to back off.

Since June last year, Hong Kong has been gripped by often-violent clashes between anti-government protesters and police, sparked by a piece of extradition legislation which officials have since withdrawn.

On August 31, police stormed Prince Edward station to chase and arrest protesters, some of whom were injured in the raid. It sparked public concerns over whether officers had used excessive force.

Between June and January, police fired more than 16,000 rounds of tear gas, 10,000 rubber bullets, 2,000 beanbag rounds, as well as 19 live rounds. More than 2,000 people were injured, including 550 police officers.

As of January 19, 7,143 people had been arrested in connection with the unrest.

Before Saturday’s renewed clashes, demonstrators went to exit B1 of the station to lay floral tributes. Officers from Mong Kok Police Station cleared the flowers and urged the crowds not to gather, but the protesters returned and continued the mourning.

The force said on its official Facebook page that the group outside the police station was blocking Nathan Road and Prince Edward Road. It said some pointed laser pointers at officers, hurling petrol bombs and causing fires on roads, jeopardising public safety.

“Police urged everyone at the scene to leave immediately and stop charging police cordon lines,” the post read.