A day after interrogating one dissident, Chinese police brought two government critics in for questioning Thursday, apparently over their plans to organize a political opposition party.

The police action against would-be members of the China Democracy Party comes amid renewed signs that Communist Party leaders are narrowing the limits of dissent.Security agents detained a prominent journalist and co-editor of a book on political reform earlier this month.

Human rights groups also reported Thursday that Fang Jue, a government official-turned-democracy campaigner who disappeared nearly eight weeks ago, was in police custody. His sister saw him July 25, the last family member to do so, said New York-based Human Rights in China.

Police in Beijing brought in Ma Shaohua, a leader of the 1989 Tiananmen Square democracy movement, on Wednesday night and questioned him for four hours before releasing him, said the Hong Kong-based Information Center of Human Rights and Democratic Movement in China.

Police also sealed off the frequently watched Beijing home of Ren Wanding, a prominent figure in the dissident community, and told him not to go out, the rights group said.

Thursday, police entered the house and took Ren in for questioning, his wife Zhang Fengying said. She said they gave no indication how long Ren would be gone.

An hour later in Shanghai, China's business capital 700 miles to the south, police also took away another dissident, the Information Center's Lu Siqing said.