BEIJING -- China's State Internet Information Office (SIIO) said on Thursday that it is waging a war against rumors spreading online as they "have impaired the credibility of online media, disrupted normal communication order, and aroused great aversion among the public."

"An extreme minority of netizens had been spreading various rumors online, with some slandering others with fabricated pictures and some deliberately spreading rumors under the pretext of seeking others' help to dispel these rumors," according to an SIIO statement.

The body is engaging in a crackdown on those fabricating or spreading rumor online.

Amid the crackdown, at least 11 people in the provinces of Guizhou, Zhejiang, Shaanxi, Gansu and Liaoning had been detained by police for spreading online rumors about the deadly H7N9 bird flu virus in the past month.

They were detained for up to 10 days for fabricating online posts about H7N9 infections that caused panic among some netizens and local residents.

The SIIO closed more than 20 microblogging accounts used by these people to disseminate the rumors.

It vowed to keep taking "a high-handed approach" against online rumors so as to maintain legal sanctity and a normal and orderly online environment.

According to the statement, the office will continue to punish Internet companies that fail to stop the spread of rumors, which lead to bad social influence, and award whistle-blowers of online rumors in the future.