Yesterday more than 40 network operators including Sina (SINA), Sohu (SOHU) and Netease (NTES) announced the establishment of the "China Youth Network Safety Alliance".

The companies said they are committed to avoiding the placement of online content and services harmful to the growth of youngsters in China. They also pledged to strictly monitor content posted by others on their website.

The group said once unhealthy information is identified, it will be immediately removed.