It's a parent's worst nightmare. And it's becoming a nightmare for China.

An attacker with a cleaver hacked to death seven children and two adults at a kindergarten in northwest China on Wednesday, the latest in a string of savage assaults on the country's schools. Eleven other children were wounded.

This latest incident at a kindergarten in northwest China was the fifth major attack on children in a couple of months.

Each assault involved a lone male.

Wednesday's killer, 48-year-old Wu Huanming, returned home after the attack on the outskirts of the city of Hanzhong and committed suicide, the local government reported.

Sociologists suggest it could be caused by a lack of help for the mentally ill in the country and also in part caused by the rising stress levels caused by inequalities in Chinese society as some prosper and many struggle.

For someone who has visited China frequently over the past 20 years I have seen dramatic changes but it's nothing to what the people there must have felt.

Going from Maoist uniforms and bicycles to Gucci hand bags and Mercedes in a few short years would be a shock to anyone.

And it's probably an even bigger shock to the Chinese in comparison to other societies as its people have come out of a life that always prided itself during the Maoist years on equality and lack of materialism.

Of course as you travel in China it's easy to see the difference now between the upwardly mobile and those fighting to survive.

Amongst the glittering skyscrapers of Beijing or Shanghai there is sometimes a glimpse of the struggles many are facing.

Once I saw workers, all men, fighting their way to the front of a crowd to get a ticket off a foreman to get work for the day, perhaps at a building site.

There are also unbelievable pressures on Chinese men to be successful now.

China's one child policy has created a disproportionate number of males to females as Chinese families traditionally favor boys.

At a basic level the chinese male is now competing with a lot more males to be successful, get a bride and have a family.

It doesn't, of course, explain these series of attacks on children.

But it's not something that is unique to China.

Japan has had similar cases in the past.

The Chinese authorities seem to be trying to downplay the incidents in the media.

Their defense being that they don't want to start a wave of panic, and some experts in China say coverage could also inspire copycat attacks.

The Associated Press contributed to this report.