Beijing: Gates and cameras have been installed at schools. Security guards have been trained to fend off knife-wielding attackers. China's top security official convened a nationwide conference call, ordering underlings to protect children when they attend classes.
But on Wednesday, the latest in a streak of copycat assaults was also the most deadly: a landlord with a kitchen cleaver barged into a kindergarten in central China, hacked to death seven children, their teacher and her mother and returned home while rescuers rushed to the scene before taking his own life.
What prompted the attack -- the fifth assault on schoolchildren since March -- was as imponderable to many Chinese as the details were gruesome. They have all involved middle-aged men in small towns expressing violent grievances against the most vulnerable and cherished members of their communities, the children of families often limited to having only one.
But whether the problem is weak diagnosis and treatment of mental illness, lackluster security and little money for schools, too much media attention to spectacular crimes or too little public debate about social inequality, the killings have presented an unusual political and security challenge to the ruling Communist Party. And in the frenzied speculation about why people might want to mimic horrific attacks on children at schools, causing problems for the powerful is believed to be one possible motive.
"They choose children because it'll have the largest negative impact on society," said Tang Jun, a sociologist in Beijing. He said the attackers did not appear to know their victims personally, so the assaults "must be an expression of their dissatisfaction with society."
The senseless suffering of children has become something of an Achilles' heel for President Hu Jintao and Prime Minister Wen Jiabao. They have presided over an extraordinary economic expansion and a rapid rise in China's global influence. But they have not been able to keep tainted infant formula off grocery store shelves or to account for why so many public school buildings collapsed during the 2008 Sichuan earthquake, killing more than 5,000 children.
Since the first in the recent spate of atrocities took place on March 23, when a man stabbed eight children to death outside an elementary school in southeastern China, the authorities have ordered the police and paramilitary troops to patrol schools. They also ordered news outlets to use only the official, terse accounts of the killings provided by the Xinhua news agency, and have kept the news off broadcast television almost entirely.
But some commentators argue that the underlying tensions in Chinese society may not be addressed by security measures and censorship.
On Wednesday, Dahe Bao, a newspaper in Henan Province, posted on the Internet a fiery editorial that pointed to misbehavior by government officials as the root cause of the problem.
"After being treated unfairly or being bullied by the authorities, and unable to take revenge on those government departments that are safeguarded by state security forces, killers have to let out their hatred and anger on weaker people," said the editorial by a writer named Shi Chuan.
The newspaper took another bold step by criticizing government efforts to censor news of the attacks. "Any effort that attempts to maintain social stability by silencing public media is outrageously wrong," the editorial said. "It is undeniable that the media's coverage on these incidents of bloodshed may 'inspire' potential killers, but it will educate more people by raising awareness of self-protection and spur the authorities."
It was not clear if administrators had stepped up security at Shengshui Temple Kindergarten in Hanzhong, a private school not far from the city of Xi'an. By Chinese standards it is a tiny school, with only 20 students.
According to the local government's account, Wu Huanming, 48, stormed into the school just after 8:20 a.m. He used a cleaver to slash the school's administrator and teacher, Wu Hongying, 50, and a student standing by her side, killing them both. He then hacked at 18 pupils.
All the victims were taken to the hospital, most with critical head wounds, said medical officials reached by phone. Six students and Ms. Wu's 80-year-old mother died of their wounds. The others survived, but some had severe injuries.
Mr. Wu, the man said to have been the assailant, returned to his nearby home. By the time the police showed up, he had killed himself, Xinhua reported. Mr. Wu had a wife and two adult sons.
It was not entirely clear why Mr. Wu attacked the children. Citing the police, Xinhua said he had rented the building to the school. In April, he demanded that the school end its operations and return the property to him, the report said. Ms. Wu, the teacher and administrator, had asked him to wait until summer, when classes would break for vacation.
Wu is a common surname in China, and the official accounts did not make it clear whether Mr. Wu and Ms. Wu were related.
But if Wednesday's killings differed in some particulars, they were similar in other respects to those that have taken place in recent weeks. The attacks appear to be a form of Chinese terrorism. The weapons are knives, a hammer, and gasoline -- guns are very hard to obtain in China -- and the targets have been the children of strangers.
In total, 17 have died and nearly 100 others have been wounded in the five attacks since March.
The attacks have succeeded in alarming top officials. On May 3, Zhou Yongkang, a member of the Politburo Standing Committee and the country's top security official, convened police and paramilitary officials nationwide for a conference call to discuss steps to protect schools. Mr. Hu and Mr. Wen have promised action as well. After Wednesday's attack, the security and education ministries convened another emergency conference call with police officials.
Some scholars have speculated that the attacks underscore the absence of pressure-release valves in a society that is going through rapid economic upheaval, where the gap between the wealthy and the destitute is widening, and where corrupt officials often exercise power arbitrarily.
The attacks have also prompted talk of how Chinese rarely discuss mental illness. In June, a British medical journal published an analysis of mental health issues in four Chinese provinces and concluded that an estimated 91 percent of 173 million Chinese adults believed to be suffering mental problems never received professional help.
"In the past 30 years, China has seen drastic social change," said Ma Ai, a professor of criminal psychology at the China University of Politics and Law. "We believe a rapidly changing social environment has a huge influence on people's personalities. That's the deeper correlation we should attend to."