Thirty-one people went on trial Monday in two court cases for allegedly running organized crime gangs in southwest China's Chongqing Municipality.

It is expected to be the first in a series of organized crime trials resulting from investigations into 14 alleged mafia-style gangs, said a spokesman with the municipal public security bureau.

Nine people -- Yang Tianqing, Li Xianguang, Zeng Chuan, Liu Chenghu, Jian Shaokun, Liu Yu, He Pengyu, Zou Meng and Li Yu -- are on trial in First Intermediate People's Court on 10 charges, including organizing a crime gang, murder, intentionally causing injury, illegally possessing guns or ammunition, false imprisonment, robbery and extortion and forging resident identity cards.

The charges spanned the last eight years, said an official with Chongqing Higher People's Court.

Yang is accused of organizing the other eight by means of coercing them to take illegal drugs and alcohol and by involving them with prostitution.

Yang allegedly imposed strict rules on the gang members that banned them from discussing the organization's affairs with each other.

Meanwhile at in Third Intermediate People's Court, 22 people, allegedly led by Liu Zhongyong, are facing a total of 11 charges, including organizing a crime gang, murder, intentionally causing injury, disrupting public services, being responsible for major incidents at illegal coal mines, assault and illegal mining,.

The Higher People's Court official said Liu faced eight charges, including opening illegal small coal mines and hiring others to guard the mines with weapons.

The gang is alleged to have been responsible for major incidents that left three people dead, and carried out 19 other crimes that left one person dead, three seriously injured and four slightly injured.

The trial is continues, the official said.

The spokesman for the municipal bureau of public security said the number of people involved in the cases ranges from more than 10 to 70 and some cases are expected to continue for more than two weeks.