Twenty-two children and one adult are reported to have been injured at a school in China today by a man wielding a knife.

It happened in a village about 500 miles south of Beijing. As NPR's Louisa Lim tells our Newscast Desk, the attack is the latest of what has been a disturbing series of such incidents in recent years.

In May 2010, as we wrote at the time, seven children and two adults were killed by a man who hacked them to death. In the space of just three months, there were five similar incidents in China.

Louisa reported in April 2010 that there's no simple answer to the key question — Why? "People are saying that this demonstrates their real lack of mental health provisions in China," Louisa said on All Things Considered. "And also the fact that the social security net has broken down because people are moving around a lot as well. There is a real lack of social and psychological support."

Fortunately, Louisa reports that local government news outlets say that none of the children wounded today have life-threatening injuries. She says that:

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