The police said they began preparing the anti-gangs operation in the first half of the year by probing gangs accused of terrorising local people over issues including land leases, construction, private lending and mining.
The operation was commanded by the Ministry of Public Security and massive arrests started late September, the state-run Xinhua news agency reported.
More than 90 of those arrested were suspects previously known to the police, the report said.
The suspects were accused of crimes, including robbery, assault, organising gambling, forced business transaction, disturbance of public order and gun-related violence, the police said.