From AP, via CBS News (link):
Two Chinese activists have been taken away by police in Shanghai as part of a crackdown ahead of the June 4 anniversary of the Tiananmen pro-democracy protests, a human rights group said Saturday.
Mao Hengfeng, who has fought China’s restrictive one-child policy, was “forcibly taken away by over 10 police officers” on Tuesday and is being held in a detention center, the New York-based Human Rights in China said in a statement.
Xu Yongdao, who wrote a letter to U.N. Secretary-General Kofi Annan asking him to intervene on behalf of his jailed dissident son, was taken to a police station and warned against making further complaints, the group said.