Some 2,000 police officers will be deployed this evening in the Mong Kok and Admiralty protest zones and in Wong Chuk Hang, where top government officials will meet student leaders to discuss the pro-democracy sit-ins, now in their fourth week, a police source said. The source said more than 1,000 would be stationed in Mong Kok because "it is a very high risk zone". A senior officer said Mong Kok was on "the verge of a riot". "We are preparing to deal with any possible chaos if the talks break down," the source added. Protesters insisted the area had been peaceful until police tried to clear their barricades. Hundreds of police officers are expected to be stationed around the Admiralty government headquarters. Pan-democratic lawmakers and student leaders plan to increase their presence in Mong Kok to ease tensions between police and protesters after clashes erupted over the weekend. Scores were injured when police deployed pepper spray and batons to clear protesters. Protesters said they were trying to maintain the size of their protest area and that they responded peacefully to increasingly violent attacks by officers. "Police are very worried about the situation in Mong Kok and consider the unlawful assembly in Mong Kok as moving towards the verge of a riot," Chief Superintendent Steve Hui Chun-tak, of the police public relations bureau, said. Hui referred to "radical protesters and troublemakers" who made attempts to charge police cordons in a "prepared and organised manner" armed with umbrellas, plastic foam, helmets and goggles. Protesters defended their choice of gear - including safety helmets and arm pads - saying it was a direct response to officers' use of batons. Several protesters received head wounds and broken bones at the weekend. A construction worker, who gave his surname as Yeung, said he started to attend more frequently in Mong Kok with fellow workers who bonded on internet sites after seeing students beaten by police on Friday night. Yeung said that at the peak, 30 workers with no political ties joined him camping overnight in Mong Kok. Civic Passion leader Wong Yeung-tat said the group was not planning to charge the police cordon before today's talks. "We have to wait and see how the dialogue is conducted. We cannot predict how the people will react at this stage," he said. Hui would not say if police had a deadline to clear protesters. Mong Kok, he said, remained very high-risk and police asked students and children to stay away. Children stood between protesters and police on Sunday night in Mong Kok, he said, as part of a "human shield" tactic that was "extremely selfish and reckless, and totally unacceptable to the public". Pan-democratic lawmakers Fernando Cheung Chiu-hung of the Labour Party and Claudia Mo Man-ching of the Civic Party stood between protesters and police at Nathan Road and Argyle Street around midnight yesterday, calling for calm. They asked the protesters to take a few steps back from police lines. Two more lawmakers - the NeoDemocrats' Gary Fan Kwok-wai and Frederick Fung Kin-kee, of Hong Kong Association for Democracy and People's Livelihood - said they would visit the Mong Kok protest more often to prevent further clashes. "If our presence can relieve tensions and prevent police from using the chaos as an excuse to clear protesters, we may consider making our visits regular," Fan said. He would also monitor whether the police had deployed excessive force. Ivan Law Cheuk-yin, chairman of the Federation of Students' standing committee, said more members would be summoned to Mong Kok. "Our aim is to protect the safety of the protesters," he said. A 23-year-old man arrested on Saturday, accused of posting messages on an online forum to incite others to join an unlawful assembly is a Form Seven graduate, a police source said. The accused works as a waiter in his father's cafe in Yuen Long. Police are investigating whether he was hired to post the messages.