A jobless knife-wielding man injured 32 people, mostly young children, at a kindergarten in eastern China Thursday in the country's third school stabbing frenzy since last month.

All of the 29 children injured in the attack in the city of Taixing were in stable condition, a government official told AFP.

The alleged assailant, 47-year-old Xu Yuyuan, burst into a classroom with a 20-centimetre (eight-inch) knife and started stabbing the children, most of whom were just four years old, Xinhua news agency said.

Two teachers and a security guard who tried to stop the attack in Jiangsu province were also hurt. A motive for the attack has not yet been reported.

"A total of 32 people have been injured, 29 children and three adults," the government official who gave only his surname, Zhu, told AFP by phone.

"Five people who were seriously injured are now in stable condition. No one has died so far."

Photos on Chinese websites showed dozens of people massed outside the school, many apparently parents frantically searching for their children.

The attack is the latest in a wave of senseless violence that underscores wrenching social change in China, where crime rates have risen steadily since the country began opening up three decades ago.

On Wednesday, Chen Kangbing, a 33-year-old teacher reportedly on sick leave due to mental problems, injured 15 students and a teacher in a knife attack at a primary school in the city of Leizhou in southern China's Guangdong province.

Reports said he was later arrested and all the injured were in stable condition.

That attack occurred just hours after authorities in Fujian province in the southeast executed former doctor Zheng Minsheng for stabbing to death eight children and injuring five others on March 23.

Zheng, 41, used a dagger to stab children in the neck, chest, stomach and back in the city of Nanping in a fit of rage and depression after a split with his girlfriend.

Old ills such as corruption, crime and drug abuse have re-emerged in China in the wake of a loosening of social controls paralleling the transition from a state-planned to a capitalist economy.

Studies also have cited a rise in mental disorders, some linked to stress as society becomes more fast-paced and old socialist supports had been scrapped.

A study last year estimated that 173 million adults in China have some type of mental disorder -- 91 percent of whom had never received professional help.

Ma Ai, a criminal psychologist at China University of Political Science and Law, said violent outbursts may be due to rising stress and the growth of the media, with children chosen as targets by angry attackers for maximum impact.

"In recent years, we have seen some people take extreme actions. The excessive attention of the media broadcasts their pain to a large audience, so the attackers feel they have achieved their goal," he said.

Besides the school attacks, a number of other multiple killings have been reported across the country in recent months.

Last week, state press said gay singer Zhou Youping was arrested in central China after allegedly killing six men in sado-masochistic sex games that involved hanging his victims.

In February, another man, Chen Ruilong, was sentenced to death in eastern Jiangxi province for murdering 13 people including three police officers over the span of more than a decade, reports said.

Despite the rising violence, extremely tight laws that bar virtually all private gun ownership prevent death tolls from reaching levels seen in shooting attacks in other countries.