A man who hated his classmates for bullying him when he was a student of a middle school in north-western China stabbed seven current students and injured 12 others outside the school, local media said.
The attack took place in Mizhi County of Shaanxi province around 6.10pm on Friday as schoolchildren were returning home.
Among the dead were five girls and two boys. Nine girls and three boys are being treated for injuries in a hospital.
The suspect, surnamed Zhao, 28, is in police custody.
Knife attacks on children are common in China where tight gun control laws force many criminals to use knives for their attack.
These attacks show that the government’s steps to regulate the purchase of knives have not been successful.
Early last year, a man stabbed and wounded 11 children with a kitchen knife at a kindergarten in southern Guangxi Zhuang region.
In 2016, another man wounded 10 children with a knife on the island province of Hainan before he committed suicide.