Hong Kong police early today started removing street barricades at sites where pro-democracy demonstrators have been holding more than two weeks of rallies, paralysing parts of the Chinese financial hub.

Police had started moving in to clear barriers at the edges of the main protest site in Admiralty, catching some demonstrators unawares after their numbers had dwindled overnight, AFP correspondents saw.

But protesters, some of whom had been sleeping in tents, remained at the site and the police said they were intent on clearing blockages to traffic rather than ending the protests outright, as morning commuters weaved around the opposing lines on foot.

"Police urge protesters to listen to the advice of the police, not to obstruct the police action, to remove obstacles blocking the roads as soon as possible, and to leave the scene in a peaceful and orderly manner," a police statement said.

The message was relayed on-site via megaphones. The police were dressed in high-visibility jackets but not wearing riot gear.

At least two dozen police vans were parked close to Admiralty, in Central, and police were also gathering at a secondary site in Mongkok.

There was a heated stand-off yesterday as a pro-government group marched on Mongkok -- a flashpoint district which has seen ugly scuffles -- with police intervening to keep them apart from the rival activists.

Some demonstrators in Admiralty early today wielded umbrellas, which have become emblematic of the Hong Kong movement, to guard against any police pepper spray.

"I'm angry because this umbrella movement belongs to the Hong Kong students. The police (should not be) our enemy but our friends," Kim Kwan, a 21-year-old student, told AFP, decrying today's intervention.

The demonstrators are calling for Beijing to grant full democracy to the former British colony and have brought parts of Hong Kong to a standstill over the last fortnight, prompting clashes with elements who oppose the blockades and widespread disruption.

Despite repeated orders to disperse, the rallies have taken on an air of permanence, with tents, portable showers and lecture venues -- drawing thousands of people in recent evenings.

Yesterday, the city's embattled leader Leung Chun-ying said the protesters had "almost zero chance" of changing Beijing's stance and securing free elections.