The man who set off a self-made explosive device outside a Chinese kindergarten killing eight people and injuring 65 others on Thursday had a neurological disorder and had scrawled words for death on the walls of his home, officials said on Friday.
However, the Fengxian county government said class was still going, and teachers and students were not among the casualties.
The attacks on children are perhaps even more troubling in a society where many parents only have one child, thanks to four decades of draconian family planning policies.
"It's so scary", said a man surnamed Meng, who learned about the explosion online.
Authorities said the explosion was a criminal act.
Police also found materials to make bombs in the property. "At this point we believe the case is solved". Many appeared to be mothers.
Early in May, a school bus packed with kindergarten pupils burst into flames in a tunnel in the eastern province of Shandong.
Graphic images on social media purportedly showed the scene with adults and children lying on the ground.
Clothes and shoes were also seen strewn across the ground.More news: At least 19 killed in hotel attack in Somali capital
More news: British PM Theresa May To Meet Fire Survivors In Downing Street Residence
More news: Virat Kohli turns off social media ahead of clash with Pakistan
Chinese police routinely blame people with psychological problems for such attacks without providing details.
Two people died at the scene of the blast and six more died from their injuries in hospital.
Li Meijin, a professor in the department of criminology at the People's Public Security University of China in Beijing, said numerous attackers appear to the men in the prime of their life, who may be struggling to cope with pressure or difficulties in their lives.
In January, a man armed with a kitchen knife stabbed and wounded 11 children at a nursery school in the southern region of Guangxi Zhuang.
As China maintains a tight control over firearms, most attacks of violence are carried out using knives, axes or homemade explosives.
Police ascribed motives ranging from an employment dispute to a disgruntled suitor spurned by a woman, as well as simply blaming mental illness.
In 2010, almost 20 children were killed in attacks on schools, prompting a response from top government officials and leading many schools to beef up security by posting guards and installing gates and other barriers.
The blast happened at 4.50pm before school finished for the day and no students or teachers from the nursery school were among the injured, according to a statement from local authorities.