A young woman police constable is under investigation for allegedly posting on her blog photos of herself and several of her colleagues in uniform - and playing with their service revolvers.
Beijing has released no details about the case but state media say the employees are suspected of paying bribes for information on China's stance in iron-ore price talks.
He is also suspected of running a German-language Internet forum since February 2009 which distributed audio, video and text messages to recruit militants.
The male officers were arrested last month on suspicion of misconduct in a public office relating to the "trafficking of phones and drugs" into the jail, the police said.
