Four district councillors were arrested and pepper-sprayed on Sunday as hundreds gathered early to mark a year since a mob attack in Yuen Long.

On June 21 last year, around a hundred white-clad assailants with connections to triad members indiscriminately beat civilians and commuters at Yuen Long MTR station.

Police have been accused of ignoring distress calls and walking away from the scene, while riot officers did not arrive until 39 minutes after receiving initial reports.

Organising political group Tin Shui Wai Connection on Thursday cancelled the march after the force issued a Letter of Objection, however, it announced a group of Yuen Long district councillors would independently go ahead with the plan at 3 pm.

The route began at the MTR station, continued along Long Yat Road, Castle Peak Road and ended at Shui Pin Wai Light Rail stop.

Incumbent lawmaker Eddie Chu, Tsuen Wan District Councillor Lester Shum, Tuen Mun District Councillor Sam Cheung and Gwyneth Ho – who all won the democratic primaries for the Legislative Council election in September – were present.

Inside YOHO shopping mall, Chu entered into a brief argument with pro-Beijing figure Man Shek. Police later escorted Shek away from the scene.

There was a heavy police presence in the area and officers regularly conducted stop and searches, while armoured vehicles and water cannons stood by.

At around 3 pm, police set up a cordon around seven district councillors and issued a fixed fine on the basis of violating coronavirus social distancing measures, prohibiting public gatherings of more than four people per group.

Tin Shui Wai Connection members held placards reading “Police-triad collusion” at the shopping mall and unfurled a banner reading “Never forget July 21. Take to the streets to oppose police brutality” while marching.

Police raised a blue flag dozens of times warning that force may be used to end the unlawful assembly.

Some protesters chanted the slogan “Liberate Hong Kong, the revolution of our times,” which the government declared pro-independence and therefore illegal under the newly-enacted national security law.

Police also lifted a purple flag warning the crowd that they could be violating the new Beijing-imposed law, which criminalises subversion, secession, terrorism and collusion with foreign powers.

Yuen Long District Councillors Frasier Hau and Ben Ho were pepper-sprayed during a police-protester stand-off near the MTR station, according to Tin Shui Wai Connection’s official Telegram channel.

The channel reported that four Yuen Long District Councillors from its group – Hau, Leon Kwan, Lam Chun, Ng Kin-wai – were arrested in the early evening on Yau San Street on the suspicion of organising an unlawful assembly.

Ng gestured “Five demands, not one less” as he entered the police vehicle.