China Tuesday dodged questions about a weekend clampdown that saw a security show of force and detentions in response to a web campaign for Middle East-style protests, instead insisting stability was key.

Foreign ministry spokesman Ma Zhaoxu refused direct comment when asked at a regular briefing about the weekend call for a "Jasmine Revolution" and the dozens of activists who have been detained or have disappeared in recent days.

He instead highlighted the "common will of the Chinese people to focus on construction and development".

"It is the common aspiration of the Chinese people to promote social and political stability, promote social harmony and safeguard the livelihoods of the people," Ma said.

"No force can sway our resolve."

China has heavily censored or blocked media reports and Internet searches about the unrest, and comments from officials and state media hint at growing official concern about the possibility of widespread unrest in China.

On Sunday, only a handful of protesters turned out amid a heavy security presence in Beijing, Shanghai, Guangzhou and other cities.

That same day, the country's powerful security czar, Zhou Yongkang, said authorities needed to "make efforts to nip in the bud social contradictions and disputes" and work to improve the "healthy development" of the Internet.

China has a huge Internet censorship system that blocks content deemed objectionable by the ruling Communist Party.

A domino effect of political upheaval that began in Tunisia has spread across the Middle East and North Africa, toppling presidents in Tunisia and Egypt and sparking unrest in Libya, Yemen, Bahrain and elsewhere.

China on Tuesday urged Libya to ensure the safety of its nationals after hundreds of Chinese construction workers fled attacks at their work site amid violent unrest in the North African nation.

"China has made urgent representations to the Libyan side, requiring it to conduct investigations (into the attacks) and bring the perpetrators to justice," foreign ministry spokesman Ma Zhaoxu told journalists.

He further expressed concern over the ongoing upheaval in Libya and urged Tripoli to safeguard Chinese personnel and property in the country.

More than 1,000 Chinese construction workers were forced to flee their compound in eastern Libya after gun-wielding robbers stormed the facility, stealing computers and luggage, their employer and state media said Tuesday.

Beijing had already warned its citizens not to visit Libya and urged Chinese companies to take precautions as protesters overran several cities, threatening leader Moamer Kadhafi's 41-year grip on power.

Ma said the Chinese embassy in Libya was "working hard" to ensure the safety of Chinese nationals in the country, adding that some Chinese had been slightly injured in the attacks.

According to the Beijing News, the looters raided Huafeng Company's compound in the eastern city of Ajdabiyah on Sunday night.

The workers, clutching their passports, plane tickets, food and water, were walking to Tripoli, "several hundred kilometres" away, where they hope to catch a plane to China, the report said.

A company spokeswoman confirmed the workers were walking to Tripoli but told AFP the distance was "not that long". She did not provide further details.

Huafeng, which is based in the eastern Chinese province of Zhejiang, is involved in residential construction projects in Libya.

On Monday, some 500 Libyans looted a South Korean construction site west of Tripoli, injuring South Korean and Bangladeshi workers, Seoul's foreign ministry said.

British energy giant BP, France's Total, Italy's ENI and Norway's Statoil are among the foreign companies that have begun evacuating staff from Libya amid the escalating unrest.