Kindergarten teachers in Taiwan have been accused of drugging their students, raising alarm among parents on the island.
Blood tests found traces of sedatives, including phenobarbital and benzodiazepines, in at least eight children at a private kindergarten in New Taipei City, according to the local Education Department.
Police began a criminal investigation in recent weeks after parents complained that their children were behaving unusually.
Angela Wang, head of local NGO Taiwan Children's Rights, told NBC News that in videos sent to her by parents, the children appeared "irritable" and at times physically aggressive.
Some of the children told their parents that their teachers had given them "juice" that was "stinky and bitter," said Wang, who helped organize a demonstration outside government offices on Sunday.
"If they refused to take it, they would be punished," she said. "They had been beaten by the teachers and some had been locked in the toilets."
Staff members at the kindergarten have been questioned, local media reported. Calls and messages requesting comment from the school went unanswered on Wednesday.
At the demonstration on Sunday, hundreds of parents and others demanded that officials share their findings as soon as possible.
"Parents are afraid and very worried," said Chen Nai-yu, a New Taipei City councilor.
Chen said three parents had contacted her for help in getting an explanation from the government.
"They don't know what to do, and they have to deal with their panic by themselves," she said. "Even if no traces were detected in some children, their parents are still desperate to know what exactly happened."
Officials have revoked the license of the kindergarten, a branch of Kid Castle Educational Institute, and fined the directors 150,000 Taiwanese dollars ($4,855), the Education Department said.
"We are very saddened by this social justice case in this private kindergarten, which has caused concerns from the public," the department said in a statement on June 8. "Please face up to the positive actions the government has taken. We hope all walks of life would cooperate with the judicial investigation to uncover the truth as soon as possible."
In response to the outcry, Taipei City Hospital, a government facility, has also been offering free drug tests for children.
A similar situation was reported this week at the other end of Taiwan, in the southern city of Kaohsiung. The city health department said Monday that four doctors had been found to have improperly given children drugs containing phenobarbital.
Both phenobarbital, which is often used to treat epilepsy and seizures, and benzodiazepines, which are used to treat anxiety, can be habit-forming. Some of the most common trade names for benzodiazepines include Valium, Xanax and Klonopin, according to the National Institutes of Health.
In Taiwan, phenobarbital is strictly regulated and can be obtained only with a doctor's prescription.
"So if a kid doesn't have epilepsy or other related diseases, it shouldn't have been possible to detect any level of this drug," said Tsai Wen-hsin, a child neurologist registered in the Taiwan Child Neurology Society.
This article was originally published on NBCNews.com