Police in Chongqing municipality have tightened online monitoring since Saturday as part of a three-month school security overhaul.

Local fears about the recent attacks on schools were renewed when media reported on Friday that a father in the city's Fengjie county, who claimed his baby died from drinking melamine-tainted formula, was sent to a labor camp for reeducation after he made Web posts saying he would kill children in revenge.

Liu Guanglei, secretary of the political and legislative affairs committee of the Communist Party of China's Chongqing committee, announced a comprehensive overhaul of campus security will take place from July 10 until Oct 10.

"(We should) prescribe drastic medicines to completely eliminate factors that undermine school security," Liu told a teleconference, the Chongqing Morning News reported.

Chongqing police and relevant authorities also issued 10 online content bans, prohibiting "pornography, rumors, false reports about dangerous or epidemic situations on campus networks, or other means of intentionally disturbing school education".

Officials with the municipal police bureau's political department told China Daily on Sunday that they could not elaborate on how local police determine what content crosses the line.

But the page bottom of Chongqing University's Web forum showed an icon that depicted a police officer blinking while sitting behind a board that read: "Chongqing Web Police".

The municipality's police and prosecutors had earlier confirmed that they registered on the popular Tianya forum to interact with netizens. They announced they had detained a Web user one day after he posted on the forum that he would become the "Chongqing version" of the murderer who went on a rampage at a school in Fujian in May.

Liu's call for increased security and the issue of the new bans came on the same day as a school security report by the local news website cqnet.com.

Parents in Fengjie county's Xinglong township have continued picking up their children from school every day, it said.

Tang Lin, the father sent to a labor camp, believed his 1-year-old son died from drinking melamine-tainted milk powder in 2008.

He had brought his case to the local health authority and petitioned to the local and central government but without result, it reported.

The angry father then posted words suggesting extreme actions on a private online community established by the melamine babies' parents on May 17, when the nation was shocked by a slew of fatal attacks at schools, it reported.

He reportedly said, "I'll take the extreme (measures)", "The news will break in days", and "I have everything ready".

His wife said police arrived at their home and apprehended him two days later.

Five attacks on children in China over the last two months have left 17 dead and dozens injured, creating nationwide fears of copycat killings.