China has ordered local officials to head off any protests that could tarnish the Olympics, the government said Monday, after a violent riot by 10,000 people threw the spotlight on deep social tensions.

Local governments across the country were told in a weekend teleconference to go "all-out" to prevent regional grievances from escalating to the point that they mar the August 8-24 Beijing Games, various official accounts said.

"Ensuring a smooth hosting of the Beijing Olympics has become a battle that all (government) levels and departments must win," said one report of Saturday's teleconference posted on the government web site of Deqing city in eastern Zhejiang province.

"From now on, we must go on a war footing," it added.

As the teleconference, organised by the central government, was being held, about 10,000 residents of southwestern Guizhou province rioted over the alleged rape and murder of a local girl.

Authorities have ordered those involved to surrender over the riot in Weng'an county, where government and police facilities were set ablaze.

Public anger was triggered by reports that local officials were protecting the suspect, who has been identified as the son of the county's deputy chief.

Residents told AFP that order had returned Monday amid a heavy police presence.

China sees thousands of such outbursts each year as ordinary Chinese -- faced with an unresponsive legal system, rampant official corruption and no free media -- resort to street protests.

China typically cracks down harshly on such action and metes out stiff punishments for protesters.

However the nation's ruling Communist Party has been desperate to portray a stable and harmonious nation ahead of the August Beijing Olympics.

Human rights groups have repeatedly accused the government of a massive campaign to quell all forms of dissent.

This has included the detention of thousands of people in restive areas such as Buddhist Tibet and Muslim Xinjiang, as well as the intimidation and jailing of dissidents in Beijing, the rights groups and other critics have said.

The weekend's orders focused on the handling of the countless commoners' petitions, which typically seek redress over injustices often committed by government officials.
The central government urged that they be handled in a way to prevent them exploding into large protests and to discourage petitioners from taking their grievances to the central government in Beijing with the Olympics approaching.

Officials should "earnestly solve the reasonable appeals of the masses," said the government of the city of Anshun, in Guizhou.

However, another account also said local governments should "strictly deal with any unreasonable troublemakers or matters that disrupt the normal social order."

The latter approach appeared to have been taken in Weng'an, where more than 2,000 armed police have been sent to quell the unrest, the Hong Kong-based Information Centre for Human Rights and Democracy said Monday.

It added that more than 300 people had been arrested.

The dissident website Boxun.com featured a photo of a public notice ordering those involved in the rioting to turn themselves in.

The anger in Weng'an was further fuelled by the death in police custody of the girl's uncle after he protested the handling of the case, locals told AFP.

The state-run China Daily newspaper on Monday quoted officials as saying 10,000 protesters had taken to the streets due to "officials' alleged attempt to cover up a murder case of a girl student."

Phone calls by AFP to the local police station went unanswered on Monday.

Although numerous Internet postings on the violence were seen over the weekend, few could be found Monday. The government's Internet censors typically block information on such clashes.