Locals claimed that when the school was being built, workers found mass graves containing bones of people who had been tortured by a local Mafia before they were murdered.
"It is known that years ago there were many victims of terrorism here," paranormal investigator Franklin Steiner said. "When this school was built, some say bones and dead bodies were found."
Other locals speculated that the school children may have played games used to contact demons, such as Ouija board.
The first cases emerged in April, and by early this week, about 80 students at the school had experienced the condition, said baffled health authorities who struggled to contain the epidemic.
"We don't understand how this has kept on going on," said Doctor Antony Choy, according to Peruvian Panamericana TV. "We know it started on 29th April and now it is still happening. Now there are almost 80 pupils [still affected].
School teachers said the attacks occurred in several classes. While some students convulsed, fainted, and experienced frightening hallucinations, others suddenly became sick and threw up.
A parent, Elsa de Pizango, whose daughter was one of the victims, told the TV station that her daughter fainted at school.
"They didn't say anything at the hospital. She just fainted. She keeps on spitting froth from her mouth," she said.
A schoolgirl, one of the victims, described her experience.
"It's disturbing for me to think about it," she said. "It's as if someone kept on chasing me from behind. It was a tall man all dressed in black and with a big beard and it felt like he was trying to strangle me. My friends say I was screaming desperately, but I don't remember much."
Another said she felt pressure on her neck as if she was being strangled, and according to classmates, she was screaming.
Her classmates said she screamed repeatedly, "Take it out."
"Several children from different classrooms fainted at the same time," a 13-year-old student said. "I got nauseous and started vomiting. I heard voices. A man in black chased me and wanted to touch me."
Although locals said the strange incident was caused by a "demonic attack," social psychologists and mental health experts say incidents of contagious hysteria are linked to fear and anxiety spreading within a group, such as students anxious about upcoming examinations.
Collective anxiety and fear may manifest among susceptible individuals as patterns of contagious collective symptoms or behavior, such as mass psychogenic illness where many members of a group present with similar or identical symptoms of disease in the absence of organic illness.
In other instances, the symptoms are wholly psychological in nature and may involve collective obsessional behavior or delusional beliefs, such as irrational conspiracy theories.
This is not the first time that contagious hysterical behavior has been reported among schoolchildren.