Six pro-democracy activists were arrested yesterday for taking part in an unlawful assembly inside the compound of the central government's liaison office on Christmas Day. One of them, Richard Tsoi Yiu-cheong, vice-chairman of the Hong Kong Alliance in Support of Patriotic Democratic Movements in China, described the arrests as 'political prosecution'. He said the scale of the action against core members of the alliance was unprecedented. Five of those arrested - Tsoi, lawmaker Lee Cheuk-yan, former legislator 'Long Hair' Leung Kwok-hung, Leung Kwok-wah and Li Yiu-kee - are members of the alliance's standing committee. Koo Sze-yiu, of the April 5th Action Group, was also arrested. Four were picked up at their homes yesterday morning, while Lee and Koo were arrested when they went to police headquarters in Wan Chai in the afternoon. They were charged with unlawful assembly inside the compound of the liaison office in Sheung Wan. They will appear in Eastern Court next Thursday. The Civil Human Rights Front accused the police of 'white terror' by arresting protesters in their homes. During the protest against the 11-year imprisonment of mainland dissident Liu Xiaobo , about 20 protesters stormed into the compound of the office when the gate opened to let out a vehicle. There was a scuffle with police and security guards inside the compound. A policeman, a security guard at the liaison office and two protesters needed hospital treatment. The liaison office said after the protest that it 'strongly condemned' the protesters. Tsoi said the prosecution was related to the office's attempt to stop protests outside its building. Lee said: 'The human rights condition in Hong Kong is retrogressing to the level on the mainland.' The chairman of the League of Social Democrats, Andrew To Kwan-hang, has been charged with assaulting a police officer during a National Day protest outside the liaison office. Two activists were arrested over a fracas outside the office during a democracy march on New Year's Day. Liaison office deputy director Zhou Junming emphasised that peace and rule of law were vital for Hong Kong. 'Harmony is in the benefits of Hong Kong and Hong Kong citizens. What will happen to Hong Kong if disorder takes place everyday? What will citizens think?' Executive Council convenor Leung Chun-ying said: 'I believe the government will act in accordance with the law. Finally, it will be for the court to rule.'