WTF IS GOING ON IN CHINA? THIS IS THE FOURTH HAMMER ATTACK ON SCHOOL CHILDREN!

BEIJING - A farmer wielding a hammer attacked kindergarten students Friday, injuring five, before burning himself to death in the third horrific assault on Chinese schools in as many days, state media reported.

Wang Yonglai used a motorcycle to break down the gate of the Shangzhuang Primary School in the eastern city of Weifang and struck a teacher who tried to block him before hitting students with the hammer, the official Xinhua News Agency said.

Wang then grabbed two children before pouring gasoline over his body and setting fire to himself. Teachers were able to pull the children away to safety, but Wang died. None of the five injured students had life-threatening injuries, Xinhua said.

The attack was confirmed by a staffer at the Weifang Public Security news office in Shandong province, but the motive for Wang's rampage was unclear. Xinhua described him only as a local farmer.

Most of the recent school attacks have been blamed on people with personal grudges or suffering from mental illness — seen as a growing problem because of feelings of social injustice and alienation in the fast-changing country.

The government on Friday issued an urgent directive to schools to tighten security.

The hammer attack follows a rampage Thursday by a 47-year-old unemployed man armed with an eight-inch (20-centimeter) knife at a kindergarten. Some 29 students, aged 4 or 5 years old, were wounded, five of them seriously at the school in Taixing city in neighboring Jiangsu province.

And on Wednesday, a 33-year-old former teacher broke into a primary school in the city of Leizhou in southern Guangdong province and wounded 15 students and a teacher with a knife. The attacker had been on sick leave from another school since 2006 for mental health problems.

In all, there have been five such attacks on schools in just over a month and many more in preceding months and years — although gun crime and other extreme violence in China is comparatively rare. Sociologists suspect the recent school rampages — usually by lone, male attackers — could be copycat actions.

The Education Ministry's directive Friday, posted on its website, called for schools and local education departments to "strengthen the security activities at schools to ensure the safety of students and teachers," particularly at particularly elementary and middle schools.

It urged "concrete actions" including strictly implementing a rule already on the books to register all visitors coming to school campuses and preventing unidentified people from entering.

Calls for beefing up security at schools are nothing new. They were initially ordered by the central government in 2004 following an attack that year that left nine students dead at a Beijing school. Since 2006, schools have been required to register or inspect all visitors.

According to news reports, the latest attacks have prompted schools in various parts of the country to take action. In a district of southern Nanjing City, guards will be armed from Saturday with police batons and pepper spray. In Beijing's Xicheng district, guards at kindergarten, elementary and middle schools have been given long-handled metal restraint poles with a hook on the end. In eastern Jinan city, police posts are being built on elementary and middle schools campuses.

In an editorial Friday, the English-language China Daily said that security should be tightened at all schools nationwide, but stressed the need to prevent attacks in the first place.

"It can be easy to put killers on trial and execute them but it is far more difficult to find out the deep-seated causes behind such horrifying acts. Our efforts should be focused on preventing these from happening," it said. "We should find out what propelled them to such extremes. What problems do they have? Could anyone have helped, especially the authorities?"

Accounts in China's state media have largely glossed over what motivates attackers, but experts say outbursts against the defenseless are frequently due to social pressures. An egalitarian society only a generation ago, China's headlong rush to prosperity has sharpened differences between the rich and poor, while the public health system has atrophied.

China likely has about 173 million adults with mental health disorders, and 158 million of them have never had professional help, according to a mental health survey in four provinces jointly done by Chinese and U.S. doctors that was published in the medical journal The Lancet in June.