China has announced plans for an anonymous tip-off website that offers rewards to members of the public for reporting those who criticise the ruling communist party or the army.

The website will allow users to give information about people they suspect of "challenging the party's absolute control over the army" or "disrupting the relationship between the army and politics".

Other offences listed included "insulting or defamation of military members or units" and "damaging the image of the army”.

Unspecified rewards would be given to those reporting useful information.

According to state media the move was aimed at providing a way for people to make "national security tip-offs".

The website will be launched on Jan 1 and feature videos promoting the importance of respecting military figures and their uniforms.

It could also be used for reporting soldiers who break rules, the government-controlled news agency Xinhua reported.

Soldiers caught engaging in "gambling, drug trafficking or other crimes" could be reported anonymously through the website, Xinhua reported.

Other activities by soldiers that could be reported included "stealing or leaking military secrets" and "fabricating information" about the army.

The latter offence echoed the vaguely defined crime under Chinese law of "spreading rumours," which many opponents of the Chinese government have been charged with and jailed for since President Xi Jinping took power in 2012.