An American teacher at a French school in Shanghai has been detained on suspicion of sexually assaulting seven children, police said last night.

The 32-year-old, identified only by his surname, McMahon, had been teaching English for five years at the Lycee Francais de Shanghai.

The kindergarten teacher was seized by police on May 13 after seven families filed formal accusations against him, alleging sexual abuse and rape of students of both sexes, several parents said.

"As parents, we are devastated," said the mother of one pupil.

Management at the school told AFP: "Families have lodged complaints with the Chinese police against a teacher at the French school of Shanghai over assaults on their children.

"The investigation is being carried out by the Chinese police and is ongoing. The teacher has been in administrative detention."

Police said that a French student, accompanied by her parents, reported to the police on May 12 that McMahon had molested her several times. McMahon was taken away by police the next day.

"It was terrible. I felt angry when I heard it. Those poor kids," another mother told Shanghai Daily last night.

Her daughter is a student at the school but not one of the alleged victims.

"We've heard about such crime overseas but were still shocked when it happened so close to us," the mother said.

The school has arranged psychological counseling courses for parents of the students involved and other concerned parents.

One mother said her child started behaving oddly soon after they moved to Shanghai and attended the French school.

"My daughter was having nervous breakdowns, she was scratching herself on her face and thighs," she said.

"As we had just arrived in China I figured it was exhaustion from moving countries, I didn't worry about it," she said, adding that only later did she link the unusual behavior to abuse.

A similar case

The fee-paying school declined to provide precise details of the accusations against the teacher, nor what period they allegedly took place.

A notice addressed to families referred to "sexual assaults."

Another mother said she suspected her daughter had been abused over a period of months, and that cases of abuse of other children went back as far as five years.

"We are living a nightmare," she said.

The news comes after a former instructor at the school, also an American, was extradited to the US on similar charges.

The former instructor, a friend of the accused teacher, was "extradited by Chinese authorities to the United States in December 2012 following an investigation into sexual touching and violence against minors," the school said in an e-mail.

From 2005 until last year he worked alternately at the French and German schools, which share a campus. He left the French school in 2011 and its management said his alleged actions took place during individual classes at a private home when he was no longer on its staff.

One parent expressed frustration, saying: "The French school wants us to believe that there is absolutely no link between these two incidents, except that the two people, while they were working together, were friends."

The French school in Shanghai is a private institution contracted with the Agency for French Teaching Abroad, a government body.

It has two campuses with about 1,600 students, mostly French and German, ranging in age from three to 18. The average tuition for a kindergarten student is 70,000 (US$11,408) to 100,000 yuan per year.

The US Consulate in the city declined to comment yesterday.