BEIJING (CNN) -- Police detained several prominent dissidents and pro-democracy campaigners on Tuesday in a concerted crackdown apparently aimed at crushing a budding opposition party.

In one of the harshest operations since pro-democracy activists set up the opposition China Democracy Party in June, police in Beijing descended on the home of Xu Wenli, 55, and took him away, his wife He Xintong said Tuesday.

Xu, who has already spent 12 years in prison for his political beliefs, is the chairman of the newly founded party's branch in Beijing.

Xu

About 20 policemen ransacked his Beijing apartment, seizing a computer, a fax machine, address books, video tapes, a typewriter, a telephone and hundreds of pages of documents, He said.

"Xu Wenli could be detained for one month," she said. "In the past, he was summoned for questioning. This time, he was formally detained as a 'criminal suspect.'"

Arrests elsewhere

In the central city of Wuhan, police also led away Qin Yongmin, another prominent activist who has repeatedly been jailed during the past several years. The authorities told his family on Tuesday that he was charged with plotting to overthrow the government.

Qin

Qin and Xu are considered to be among the most influential figures in China's fractured and persecuted dissident community. Their campaigning for democratic reforms started in the 1970s.

Police in Wuhan also led away party members Chen Zhonghe and Xiao Shichang, according to Hong Kong-based Information Center of Human Rights and Democratic Movement in China.

Another party member, Lai Jinbiao, was detained on Monday afternoon in the eastern city of Hangzhou after making a speech in a public park, where he demanded that the ruling Communist Party carry out political reforms, the center said.

CNN has further learned that former pro-democracy student leader Wang Youcai -- who has been in and out of prison for the past months -- was charged with violating parole regulations.

The founders of the Chinese Democratic Party have been emboldened by China's signing in October of the U.N. International Covenant on Civil and Political Rights, which among other things guarantees freedom of assembly and speech.

Li Peng, chairman of the Chinese parliament, ruled out Western-style democracy and multi-party politics in an interview published by the German business daily Handelsblatt on Tuesday.

"China promotes democracy and practices rule of law but our road is not patterned on the Western approach that features the separation of powers, multi-party system and privatization," he told the newspaper.

"Such a system may be suitable to the West. However, China has its own conditions. We are a developing country with a large population," Li said.

He emphasized that anti-Communist parties would not be tolerated.

"If it (the new party) is designed to go for the multi-party system and try to negate the leadership of the Communist Party, then it will not be allowed to exist," Li said.

Beijing Bureau Chief Rebecca MacKinnon, The Associated Press and Reuters contributed to this report.