Wolf said four of the computers in his office were breached in August 2006 and authorities traced the activity back to a computer in China, The Washington Post reported. Computers of "several others" on Capitol Hill also have been attacked, Wolf said on his official Web site.

Wolf said the hackers reached sensitive information about the identities and locations of Chinese dissidents, and other data.

Rep. Christopher H. Smith, R-N.J., another critic of China's human rights record, said he was targeted by hackers twice, noting the sophistication of the efforts and the type of information retrieved suggested the Chinese government may have been behind the attacks.

"The Internet can be used as a terror weapon. It can be used as a disinformation apparatus," Smith said. "And nobody has done that more expertly than the Chinese government."

The congressmen didn't name any of the others they think were targeted by hackers.