BEIJING - Chinese police uncovered about 670 secret sites involved in the illegal production and distribution of guns in 2012, according to official figures unveiled Tuesday.

The Ministry of Public Security released key figures on the results of last year's national campaign to fight gun-related crimes, which has been considered a success.

Statistics show that police authorities across China last year investigated around 14,000 cases involving a range of illegalities, including the production, trade and possession of guns and explosives.

More than 20,000 people were apprehended for their suspected involvement in such crimes and some 360 criminal gangs were busted, according to the ministry.

The ministry said police seized around 160,000 guns and 2,780 tonnes of explosives during the campaign. More than 60 percent of all seized guns and ammunition was submitted by citizens voluntarily or confiscated by police acting on tip-offs.