A march in support of Chief Executive Leung Chun-ying turned nasty yesterday as two journalists were punched and harried by supporters.
And scuffles erupted on the march from Victoria Park to the Tamar government headquarters as anti-Leung campaigners arrived carrying colonial Hong Kong flags.
Organizers said more than 30,000 took part but police estimated only 2,600 were in the parade.
The pro-Leung rally came just ahead of tomorrow's New Year's Day march aimed at forcing Leung out of office.
A reporter and a cameraman from Now TV were slightly injured during a clash with a dozen demonstrators in Victoria Park.
A middle-aged man was taken away by police after he allegedly thumped the head of the cameraman during the five- minute fracas.
The ugly moment came when reporter Chau Chi-wing and cameraman Lau Ka-wo were interviewing a Leung supporter before the march began.
"I was asking the supporter about Leung's policies but he thought I was questioning Leung's integrity," Chan said.
"Then he and the others started to ask me whether I had any integrity. "As they became more emotional, some pulled at our camera lens and microphone lines."
A dozen people surrounded the two, telling them to "shut up" and calling them "traitors."
Several men pushed Chau and Lau. In the scramble Chau's glasses fell off and were trampled upon by other supporters.
Video footage shows a man punching Lau on the back of his head.
Officers took away the man, who waved a SAR flag, in an assault probe.
Chau was injured in his right eye while Lau has a lump on his head.
Now TV said the case has been referred to the police.
In a second incident near the Sogo department store in Causeway Bay, a group with colonial flags scuffled with Leung supporters.
Yesterday's pro-Leung rally was organized by the group Caring Hong Kong Power, which had expected to gather 5,000 Leung supporters.
A 75-year-old retiree Yiu Lau-yan, who joined the rally, accused legislators of not giving the chief executive enough time to carry out policies.
"Many legislators also have illegal structures in their homes," he said. "Why do they only focus on the chief executive and not reflect about their wrongdoing?"
The Voice of Loving Hong Kong - another group expressing support for Leung - says it expects as many as 1,000 people to turn up for its own march and carnival at Tamar Park tomorrow.
At the same time, the Civil Human Rights Front has organized an anti- Leung protest tomorrow, expecting 50,000 people to to demand he step down. Leung survived a vote of no confidence in the legislature earlier this month over illegal structures in his home.
He faces a planned impeachment motion early next month. Protesters will march to Tamar tomorrow and will stay at government headquarters, close to where the group supporting Leung will have a carnival.
Political commentators warn the atmosphere will be tense and called on the police to act promptly should there be trouble.