More than 50 school children underwent hospital treatment Friday after developing what educators called mass hysteria, marked by fainting and screaming.

Firefighters immediately shut down Dakar's Lamine Gueye Secondary School and Senegal Minister of Education Moustapha Sourang ordered an investigation.

"It's the first time that I have seen such a phenomenon," Sourang said.

Fifty-three teenage girls and two boys were treated at the capital's main hospital, said principal Adina Aidara.

"The phenomenon started in one of the classrooms," Aidara said. "Three students, all girls, fell down. The same phenomenon was repeated 30 minutes later during recess."

Worried parents fussed over their daughters at the hospital, and some allowed their girls to be interviewed on condition that their name not be published.

A 15-year-old girl said that she was in the middle of chatting with a friend. "Suddenly I had a horrible headache. It hurt so much that I started screaming. And then I fainted. From that moment on, I no longer knew where I was," she said.

Doctors didn't immediately provide a medical diagnosis, and rumors began circulating in the city linking the incident to supernatural involvement.

Chief hospital psychiatrist Ababacar Wilane tried to put it into perspective, saying many of the students were "probably caught up in the moment and succumbed to a kind of domino effect" when they saw the others fainting and screaming.