China has reportedly launched a new crackdown on unregistered house churches as the Nobel Peace Prize ceremony for a Chinese dissident nears.

Bob Fu, president of the human rights group China Aid, said the operation was launched Dec. 1 -- the same day his Web sites were shut down by a Chinese cyber attack.

Fu recently obtained a Chinese government-issued report that labeled house churches as a "cult."

The crackdown comes just days before the Nobel peace prize ceremony for Chinese dissident Liu Xiaobo.

China criticized the award, saying it will encourage residents to retaliate against the government. China and at least 18 other countries will boycott the ceremony.

Fu said this will be the first time in Nobel history that the award recipient's chair will be empty.

"China has put Dr. Liu of course in an 11-year sentence in prison," Fu said. "His wife has been under house arrest since the day of announcement, and all

his relatives are either under house arrest or missing."

Fu and members of the U.S. Congress will attend the ceremony.

Sources inside China told CBN News they could not confirm a crackdown against house churches.