Hong Kong says it will deploy more than 3,000 anti-riot police to stop unauthorized gatherings Friday. It expects some protests during the city's annual June 4 vigil to commemorate Tiananmen Square despite a ban on gatherings attributed to COVID-19.

Organizers of the vigil were denied their application to hold this year's gathering in Victoria Park owing to the pandemic. This is the second consecutive year the vigil had been canceled.

The Hong Kong Alliance in Support of Patriotic Democratic Movements of China said it will adhere to the ban. The alliance will not call on people to show up at Victoria Park and will also cancel a previously planned online ceremony.

The alliance is concerned about police arresting people watching the live broadcast together in public - which is against the city's current COVID-19 restrictions.

Senior police sources said five units, including those from the elite Police Tactical Unit and other teams, will be on standby across the city Friday. Officers have been told to disband any gatherings at the park later in the week.

"A lenient approach on unauthorized assemblies isn't expected as our operations need to bring deterrent effects after courts handed down lengthy jail terms to protesters," police sources said.

Under the city's current pandemic rules, gatherings of more than four people in public are prohibited. Sources said the actions of the police will depend on the behavior of protesters during the day.

"It all depends on the situation. Officers would collect relevant evidence for investigation and seek legal advice when necessary," one of the sources said.

Police sources said they had no intelligence to indicate any mass gatherings Friday. However, authorities are preparing for the worst in case of a "mass turnout." Sources said traffic police will set up roadblocks leading to the park and officers have been instructed to carry out stop-and-search checks around the venue.