China's Ministry of Public Security will launch a special investigation next month into cases of "unnatural deaths" amid police investigation and enforcement procedures, according to a statement posted Wednesday on the ministry's website.

These cases have occurred in two kinds of police-run detention centers holding suspects who are under investigation or awaiting trial, and some minor offenders, respectively.

A liability system should be established to rigorously look into each cases and hold relevant people accountable, the statement said, quoting Liu Jinguo, vice minister of public security, as saying at a working conference on Tuesday.

The police should strive to prevent new cases from occurring and intensify the education and training of newly-recruited police officers, Liu said.

Cases of odd deaths in detention centers have repeatedly stirred public concerns over the safety and transparency in the management of both these sites and police officers.

The death of 24-year-old inmate Li Qiaoming at a detention center in southwest China's Yunnan Province in 2009 extensively attracted the public's attention.

Authorities in the detention center first said Li had died while playing a hide-and-seek game, but a subsequent inquiry concluded that three other inmates had beaten him to death.

China has been making efforts to improve laws and regulations meant to stop police from using violence to coerce suspects' confessions in detention centers.

In August, China's top legislature, the National People's Congress (NPC) Standing Committee, first reviewed a new draft amendment to the Criminal Procedure Law.

The draft stipulated that all criminal suspect interrogations should be conducted in detention centers and that in the most serious criminal cases, the entire interrogation should be video-recorded.

Also, according to the ministry's statement, another campaign will be launched to check the management of bail funds as well as money and goods seized during police investigations.

Police authorities at the county level and above should set up special accounts and sites to keep such money and goods and strictly regulate the use of these items, Liu said.