HONG KONG • Police in Hong Kong yesterday said they have banned a protest tomorrow by the organiser of previous historic mass marches, citing public safety concerns, hours before a leader of the group was attacked by masked men.

Approving the Civil Human Rights Front's (CHRF) march was too risky as some people might use it to "carry out large-scale destruction and disrupt public order", Mr Kwok Pak Chung, the police force's regional commander for Hong Kong Island, said at a briefing.

"Based on our intelligence, we believe certain protesters will commit acts of violence during the gathering," Mr Kwok said. "There's a high chance that certain violent protesters will hijack this event."

Ms Bonnie Leung, CHRF's vice-convener, told Bloomberg News that the group was planning to appeal. Some previous rallies were approved at the last minute after negotiations with police.

If CHRF goes ahead with the demonstration, this would be the 13th straight weekend of pro-democracy protests.

The ban announced yesterday could trigger further outcry as the rally had been planned for the fifth anniversary of China's introduction of an electoral reform package that would have restricted democratic freedoms and was later rejected by Hong Kong.

It could also fuel turnout at a two-day general strike called to begin on Monday if the government does not concede to protesters' major demands by tomorrow, the South China Morning Post said.

The march had been planned to start at centrally located Chater Garden and continue on to China's liaison office in the city, where Hong Kong's police and Beijing have drawn their sharpest line after a previous demonstration saw protesters deface the national emblem.

The CHRF has organised three record-breaking peaceful marches over weeks of protests, including the June 9 rally against legislation easing extraditions to China that sparked what has morphed into a broader movement against Beijing's tightening grip over the city.

The group said each march brought more than one million people onto the streets, while police estimates have been lower, in the hundreds of thousands.

Its latest march would come after a weekend that began with the formation of a peaceful human chain across the city and culminated two days later with police firing a weapon and using water cannon for the first time. Police said 86 people were arrested over the weekend for offences including unlawful assembly, possession of weapons and assaulting officers.

Also yesterday, CHRF convener Jimmy Sham said he was attacked at a restaurant in the Jordan area of Kowloon by two masked men wielding at least one baseball bat and one long knife. He was not hurt as his friend shielded him from the beatings, he said in a CHRF WhatsApp media group chat.

Hong Kong police officials confirmed the attack and said officers had arrived on scene shortly after and had tried "in vain" to locate any suspects, and that the case would be followed up by a criminal investigations team.

Meanwhile, China's military deployed fresh troops to Hong Kong yesterday in what it called a routine rotation amid speculation that it might intervene in the city's pro-democracy protests

Video broadcast on China Central Television showed a long convoy of armoured personnel carriers and trucks crossing the border at night and troops in formation disembarking from a ship.

Troops stationed in Macau, another special administrative region, also completed a rotation yesterday.

BLOOMBERG, ASSOCIATED PRESS