Chinese authorities have arrested more than 10 activists who campaigned to have political leaders disclose their financial assets, lawyers said Thursday, with one charged with "inciting state subversion".

Chinese citizens are regularly scandalised by persistent reports of corrupt Communist Party members living lavish lifestyles, and activists have called for laws requiring government officials to publicly list their assets.

Newly-appointed President Xi Jinping has vowed to crack down on all forms of corruption.

But police in southern China's Jiangxi province detained activist Liu Ping, 48, in late April for "inciting subversion of state power", after she campaigned online for official asset disclosure, her lawyer, Zheng Jianwei, told AFP.

Police in Jiangxi did not answer phone calls on Thursday. They had not given a clear reason for her arrest, Zheng said, adding that it probably related to her recent activism.

In a separate case, Beijing police arrested at least 10 people after activists unfurled a banner calling for official asset disclosure in a busy Beijing shopping district last month.

"First four were arrested, then another six were arrested in connection with the incident" after police forced the small-scale protest to end, Liang Xiaojun, a lawyer for several of the activists, said Thursday.

It was not clear when the arrests occurred.

All but one of the group had been charged with "unlawful assembly", Liang said. He was unsure when the case would go to court.

The developments come after a top Chinese anti-corruption official warned against detaining petitioners who seek to alert higher authorities about graft.

State media quoted Zhang Shaolong, a senior official at the Central Commission for Discipline Inspection (CCDI), as saying that whistleblowers should receive a warm welcome from anti-corruption agencies.

China often uses state subversion charges to suppress political activists. In the most prominent case, Nobel laureate Liu Xiaobo was convicted of state subversion in 2009 and sentenced to 11 years in prison.

Bloomberg news agency last year reported that Xi's family had assets worth $376 million, while the New York Times reported that relatives of former Premier Wen Jiabao had controlled assets worth $2.7 billion.

Authorities in China sought to suppress the reports by blocking access to both outlets' websites and deleting other online items.

Some Chinese areas have experimented with limited forms of financial disclosure by officials, but the schemes have not been long-lasting.

Advocacy group China Human Rights Defenders said Thursday that Chinese authorities had "targeted activists who have taken part in the anti-corruption campaigning" as part of an "escalating crackdown on free expression".