The attack happened in the village of Chengping in Henan, a landlocked province about halfway between Beijing and Shanghai. A 36-year-old named Min Yingjun from Guangshan county is accused of bursting into the home of a 85-year-old woman before stabbing her with a kitchen knife and then moving on to children as they were arriving for school after 8 a.m. local time.
On Saturday, the Chinese government's Xinhua News Agency quoted police who said that Min was possibly "mentally ill" and is now in custody.
A doctor at Guangshan's hospital of traditional Chinese medicine said that nine students had been admitted, two of which were subsequently transferred to better-equipped hospitals elsewhere in the country. None of the children have died.
Some of the children had their fingers or ears cut off.
It's not clear how old the children were, but the primary school in China covers children between six and 11 years old.
The man attacked almost two dozen children before being subdued by security guards who have been posted across China following a spate of school attacks in recent years.
The website for the local government in Guangshan confirmed the figure of 22 injured and said an emergency response team had been dispatched to investigate the attacks.
No motive was given for the stabbings, which echo a string of similar assaults against schoolchildren in 2010 that killed nearly 20 and wounded more than 50 people. In one such attack last August, a knife-wielding man broke into a middle school in the southern city of Nanchang and stabbed two students before fleeing.
Most of the attacks have been carried out by mentally disturbed men involved in personal disputes or unable to adjust to the rapid pace of social change in China, underscoring grave weaknesses in the antiquated Chinese medical system's ability to diagnose and treat psychiatric illness.
In one of the worst incidents, a man described as an unemployed, middle-aged doctor killed eight children with a knife in March 2010 to vent his anger over a thwarted romantic relationship.
Chinese law largely prohibits the private ownership of guns.