Since the Chinese authorities cracked down on online porn over the weekend, it shut down nearly 50 additional websites and also instructed Internet giants like Google to end any sort of links with such material.

It should be noted that as a part of a month-long campaign, that the government informs is aimed at stamping out online pornography, a total number of 91 sites have been shut down or blocked since Thursday.

Warning the law-breakers to surrender themselves to police, the government informed that distributing pornography is illegal in China and if in case the law-breakers don't adhere to them, tougher measures would come in the following days.

A report by a well known Chinese news agency gave some details regarding which sites were shut down.

The report said, "China's Ministry of Public Security and six other government agencies launched the drive against sites that post or link to content that harms public morality and corrupts the nation's youth."

Google, MSN and Baidu, the most popular Chinese search engine have been included by the authorities.

All the companies that are not willing to remove obscene content or links to such material have been warned that they might be closed.

Since then, apologies have been issued by Google, Baidu and other Internet portals and most of them have moved against online porn.

On Wednesday, Google informed that all links to vulgar material from its search indexes have been removed by it. It also informed that it will go all-out to prevent such material re-appearing.