A Chinese industry organization has listed a group of websites, including Google, Baidu, Sina.com and Sohu.com, which have been found to spread pornography and threaten youth's morals, and could tighten regulations on these websites.

China Internet Illegal Information Reporting Centre (CIIRC) said it has found 19 websites that provide content that includes pictures, text, video clips and web links inappropriate for young people.

Major websites such as Google, Baidu, Sina, Sohu, Tecent and NetEase are on the list.

The announcement is part of a nationwide campaign launched jointly by seven Chinese ministries to clean up the online environment. The list exposes a number of websites that violate public morality and harm the physical and mental health of young people.

CIIRC said the listed websites did not take effective measures to take out the inappropriate content after they were noted.