Chinese state media are reporting that a Beijing court has imprisoned 10 men for illegally detaining citizens who tried to lodge complaints with the central government.

Under China's “petitioning” system, people can request that the central government investigate abuses by local officials at a complaints office in the capital.

However, Beijing's Chaoyang District Court found last month that local officials in the city of Changge in central Henan province hired men to stop petitioners from airing their grievances in Beijing in an effort to cover up abuses.

The 10 were handed prison terms of up to 18 months for illegal imprisonment.

Rights groups say petitioners are often forced to go back home or are detained in illegal facilities called “black jails.”