BEIJING - The Internet Society of China on Sunday called on the country's Internet companies to strengthen self-discipline and prevent the spread of online rumors.

The spread of online rumors has become a public nuisance which seriously infringes people's interests, national security and social stability, the society said in a written proposal.

Internet companies should take effective measures to resist online rumors by seriously obeying the country's laws and regulations as well as industrial self-disciplinary rules, it said.

Chinese authorities have closed 16 websites for "fabricating or disseminating online rumors" particularly through microblogging posts.

Beijing police have arrested 1,065 suspects and deleted more than 208,000 "harmful" online messages as part of an intensive nationwide crackdown on Internet-related crimes conducted since mid-February.

China's two major Internet portals, www.sina.com and www.qq.com, have been criticized and punished by Internet information administration authorities for allowing the spread of online rumors and other illegal information.

The two portals' microblogging sites, weibo.com and t.qq.com, were also suspended comment functions for four days to clean up rumors and other illegal information spread through them.

Internet companies should strengthen education of professional ethics among their employees and improve their ability to differentiate online rumors, the proposal said.

The companies should also comply with the government's rule for real ID authentication and at the same time well protect Internet users' personal information, it said.