WASHINGTON—Multiple congressional computers have been hacked by people working from inside China, lawmakers said Wednesday, suggesting the Chinese were seeking lists of dissidents.

Two congressmen, both longtime critics of Beijing’s record on human rights, said the compromised computers contained information about political dissidents from around the world. One of the lawmakers said he’d been discouraged from disclosing the computer attacks by other U.S. officials.

Virginia Rep. Frank Wolf said four of his computers were compromised, beginning in 2006. New Jersey Rep. Chris Smith, a senior Republican on the House Foreign Affairs Committee, said two of his computers were attacked, in December 2006 and March 2007.

Wolf said that following one of the attacks, a car with license plates belonging to Chinese officials went to the home of a dissident in Fairfax County, Va., outside Washington and photographed it.