China has launched a pornography crackdown on major Web sites, targeting popular online portals and search engine giants such as Google.

In a government announcement Monday, China listed search engines like Google and Chinese search engine Baidu, among others. The statement said the companies have failed to respond effectively to government complaints that search engine results contain numerous links to pornographic Web sites.

Baidu is the most popular search engine in China, followed by Google.

China has carried out Internet crackdowns on pornography, con artists and political activists in the past. However, its Internet police struggle to block Web sites that are based overseas.

In a written statement, Google's China-based spokeswoman, Cui Jin, defended the site's operations, stressing that it is a search engine and that it does not generate pornographic content.

Cui Jin says that if the company finds any violations, it will take action in accordance with the law.

Some information for this report was provided by AFP, AP and Reuters.