The new head of China's ruling party sounded a strong anti-corruption warning in his first speech to top politicians, state media said Monday, following a series of stern messages by top officials.

Xi Jinping stressed the theme as he and other top leaders take charge for the next decade in the world's most populous country, where public anger has mounted at perceived privileges and abuses of power in the one-party system.

"A large body of evidence has shown us that the issue of corruption is growing more intense and in the end will kill the party and the country," Xi said, according to the party-linked People's Daily and other outlets.

"We must be alert," he told the top 25-member Politburo Saturday.

"In recent years in some countries, long-festering disputes have led to popular anger, social unrest and a collapse of government power -- and in all this corruption played an important role."

Xi also warned against graft last week in his widely watched first speech as party leader, as did his predecessor Hu Jintao a week earlier in his last major address before handing over the reins.

"If we fail to handle this issue well, it could prove fatal to the party and even cause the collapse of the party and the fall of the state," Hu told 2,300 delegates at the start of a tightly scripted party congress which oversaw the handover.

Xi is expected to succeed Hu as China's president early next year in a move that would formalise his leadership of the country.

In the new lineup the respected official Wang Qishan will take over the party's "discipline inspection" body which handles corruption cases, in a move analysts said could signal a more serious intention to tackle the problem.

The party has been rocked by high-profile scandals in recent years, notably the dramatic fall of top politician Bo Xilai who now faces trial for corruption and abuse of power.

Still, analysts note that authorities have warned against corruption before, and while low-level offenders have faced punishment, truly uprooting corruption would also require tackling powerful figures and their interests.

China activists dead in custody: rights groups
Beijing (AFP) Nov 19, 2012 - At least two activists died in custody before or during China's Communist Party congress and tens of thousands had their movements restricted, rights groups said Monday.

The action was part of the government's "maintenance stability" campaign aimed at preventing any sign of unrest during the party gathering in Beijing, which ended last week, the Chinese Human Rights Defenders (CHRD) said.

The congress ushered in a once-a-decade leadership change, with President Hu Jintao stepping down from his top party post to make way for Xi Jinping, who is due to be named state president in March.

CHRD -- a nationwide network of activists in China who compile reports of human rights violations -- said Zhang Yaodong, a petitioner from Henan province, was beaten to death in police custody in the capital on November 5.

On Thursday last week, Chen Chengxiang, a petitioner from Hubei province, set herself on fire in protest over local corruption in front of the Beijing office that houses the UN Commission on Human Rights, the group said.

Beijing police refused immediate comment on the two incidents when contacted by AFP, and it was not clear whether Chen survived her suicide attempt.

Another campaign group, the Hong Kong-based Information Centre for Human Rights and Democracy, said Xu Wanxia, 53, a petitioner from the eastern province of Anhui, was detained by police in Beijing on November 8 and pronounced dead in Anhui six days later.

Xu's body was covered in bruises, prompting her family to believe she was beaten to death, the group said.

CHRD said that police had detained, put under house arrest, sent to labour camps or otherwise harassed a wide range of government critics, including political dissidents, human rights activists and academics.

The group said hundreds of petitioners, Christian activists and rights lawyers were also targeted during the crackdown, adding that "up to 100,000 people" had been affected according to "conservative estimates".

Social unrest in China has risen markedly in recent years with an estimated 180,000 protests in 2011 over a wide range of issues including corruption, government land grabs, police brutality and social welfare, studies show.

To counter the instability, China allocated $111 billion this year for "stability maintenance", exceeding the nation's declared defence budget.