BEIJING - Beijing police on Saturday said they 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.

The operators of more than 3,117 websites have received related warnings, a spokesman from the city police's cybersecurity department said Saturday, adding that 70 Internet companies that defied the warnings have received administrative punishments, including forced closures.

The spokesman said the campaign, dubbed "Spring Breeze," mainly targets the dissemination of information related to smuggling firearms, drugs and toxic chemicals, as well as the sale of human organs, the counterfeiting certificates and invoices and trade in personal information.

The crackdown is meant to address prominent public complaints about Internet-related crimes, the spokesman said, adding that reports about Internet-related crimes have gone down 50 percent since the campaign was launched on February 14.

The spokesman urged Internet users to actively oppose the spread of harmful information.

China has stepped up its efforts to "cleanse" cyberspace over the past few weeks. Beijing police on Friday announced the detention of six people for allegedly fabricating and spreading rumors on the Internet, as well as punishment for websites and social media that carried the rumors.

Sixteen websites were subsequently forced to close, and the country's two largest microblog operators -- Sina Weibo and Tencent -- have suspended commenting functions on their sites from March 31 to April 3.

A Tencent statement said the move was made to prevent illicit information from spreading through microblog posts.