A 22-year-old female teacher surnamed Liu was detained by police in Chaoyang district in Beijing after parents complained that their children were allegedly drugged and molested at RYB Education Kindergarten’s Xintiandi’s branch.

In a statement issued on Saturday, the New York-listed kindergarten said it had fired a teacher, who was detained by district police for suspected child abuse.

On November 22, some parents complained that their children were given unidentified white pills and received injections of a brown liquid. The children were made to take off their clothes before a naked man conducted “medical check-ups” on them.

There were around 20 children in a bilingual class with four teachers, including one foreign teacher, according to Xinhua News Agency.

Some children were told to take two pills each after lunch, a parent who refused to give her name, was quoted as saying in the Xinhua report. She said it was uncertain whether her child had been sexually assaulted.

“My child said the teacher told them it was a secret and they were not supposed to tell anyone else, including parents,” an unnamed mother told CNN.

The allegations began last week when a parent posted a video on Weibo. In the video, she said she and at least eight other parents reported to police that their children were being abused and molested at the school.

According to its website, RYB Education, founded in 1998, has more than 1,300 day-care centers and nearly 500 kindergartens in 300 cities in China.

The firm was reported to have issued an apology on Saturday, saying the detained teacher and the head of the kindergarten had been sacked “for a serious breach of duty in our management”.

It promised to provide counseling to victims and upgrade safety measures at its facilities.

Police reportedly detained another woman for “rumor mongering,” saying she had posting fabricated information online, claiming military personnel were involved in the incident.

That prompted a denial from the Defense Ministry, CNN reported.