Despite stepped-up security at China’s schools, another kindergarten was the scene of a gruesome rampage Wednesday when a middle-aged man armed with a kitchen knife hacked to death seven children and a teacher.

The latest in a troubling string of attacks on children took place at 8 a.m. Wednesday at the Linchang Village Kindergarten in the town of Hanzhong, about 100 miles southwest Xian, famous for its terra-cotta warriors. The killer was identified by the official New China News Agency as 48-year-old Wu Huanmin. He reportedly escaped from the scene and killed himself at home.

Some reports said he was the landlord for the school, which provided instruction and childcare for children as young as 3. Besides the pupils killed, 20 were reported injured.

A posting on the Tianya news forum said that there might have been more than one person involved and that the criminals got into the kindergarten by driving a van into the main gate. The report could not be verified.

News coverage was sketchy, with few Chinese-language websites reporting on the attack and the report from New China posted only in English. Chinese authorities have avoided publicizing such attacks on the grounds that they could inspire copycat killers.

Wednesday’s attack is the deadliest since March 23, when an unemployed doctor stabbed to death eight children in Nanping City, Fujian province. Since then, there have been half a dozen similar rampages around China, almost all of them involving middle-aged men who went after young children with knives, cleavers, axes and in one case, gasoline.

“The atmosphere is very bad these days. People are really terrified,” said a doctor who gave her name as Yu from the Shankou Village Medical Clinic, which is near the school that was attacked. She said she was leaving early to pick up her 8-year-old grandson from school.

Around the country, police and paramilitary forces have been assigned to watch schools at key hours when children are coming and going, and security guards have been trained to use batons to defend schools against knife-wielding attackers. In Nanzheng county, where Liulang village is located, a conference on school security took place May 5, exactly a week before the attack.

“It is mission impossible to prevent these attacks in the short term. More and more people have been inspired to copy what the others have done, and it is very difficult to stop them,” said Liu Shanying, a political scientist with the Chinese Academy of Social Sciences in Beijing.

China has strict controls on guns, but large knives and cleavers are found in every Chinese kitchen.

Liu said it is no coincidence that all the attackers have been middle-aged men living in small towns.

“When you look at attacks in the United States, it is usually about social isolation or pressure at school, but these are men in their 40s, who feel they didn’t enjoy the fruits of economic development and have passed the golden period where they can improve their lives,” he said.

“They feel they have no other way to express their grievances. They go after the most defenseless segment of the population, young children, in order to kill as many people as possible.”

barbara.demick@latimes.com

Nicole Liu and Tommy Yang in The Times’ Beijing Bureau contributed to this report.