Beijing - Two courts in the south-western city of Chongqing on Wednesday sentenced three men to death after convicting them of leading organized crime rings, state media said.

They were among 31 alleged members of two criminal gangs tried this week as the first of hundreds of people in Chongqing, including several top officials, accused of involvement in some of China's largest organized crime rings.

Three other members of the two gangs were given suspended death sentences on Wednesday, while the other 25 defendants were given prison sentences ranging from one year to life, the official Xinhua news agency said.

Prosecutors accused the gang members of crimes including murder, illegal possession of firearms, running illegal coal mines, false imprisonment, robbery, extortion and forgery, the agency said.

Chongqing police questioned more than 2,000 suspects during a six-month crackdown on organized crime, including 67 alleged gang leaders and 50 government officials.

Police formally arrested more than 600 suspects, while Chongqing state prosecutors had charged 263 people by the end of August.

Wen Qiang, the former director of the city's justice bureau, and a former deputy police chief were among those detained by police for questioning, earlier reports said.

Chongqing was reportedly one of China's biggest centres for weapons trafficking, while the gangs also controlled prostitution, gambling, drugs, entertainment and many local businesses, including one city bus company.

City courts also tried a major organized criminal gang in April, sentencing 19 people after convicting them of murder, drug trafficking, robbery, illegal possession of firearms, and bribing police officers.

In an editorial on Monday, the official China Daily newspaper said the provision of "protective umbrellas" to the gangs by municipal government officials and police officers was a problem of China's "transition from a planned economy to a market one." (dpa)