The Hong Kong Journalists Association (HKJA) on Saturday condemned the police for pushing and alleging shooting a sponge grenade at a Commercial Radio reporter, as well as threatening to arrest him for "rioting".

In a statement, the HKJA said the "indiscriminate force" used against the reporter in Mong Kok on Friday night was unreasonable.

The incident reportedly happened at around 1am on Argyle Street when the police were conducting a clearance operation. The reporter, who was filming at the time, was apparently pushed and shoved by officers before being accused of rioting.

When the journalist tried to zoom in on the officers' identification numbers, one of them threatened to arrest him. As he turned around and was about to leave, the reporter heard a shot and realised there was a hole in his backpack, with a sponge grenade found at the scene.

The association said it once again implored Chief Executive Carrie Lam to intervene to stop the police from hindering the work of the press.

The HKJA also called for the police to thoroughly investigate the incident.

Meanwhile, Commercial Radio issued its own statement condemning the actions of the police officer involved in the alleged violence.

It said the officer had damaged press freedom and such behaviour would do nothing to help restore calm on the city's streets.