Shaanxi province's education authority told schools and kindergartens on Wednesday not to mass-distribute medicine to their students without authorization.

The provincial Education Department's emergency notification follows allegations that 1,455 kindergartners in Xi'an received a prescription drug without their parents' permission this school year.

A mother holds her son at the gate of a private kindergarten, Hongji Xincheng, in Xi'an, Shaanxi province, on Thursday. Investigators said school officials administered prescription antiviral drugs to children. The number of children who were given the medicine was raised to 1,455. Li Yibo / Xinhua News Agency

"Any school or kindergarten that wants to give medicine to its students for disease prevention should report this in advance with a detailed plan, and it may implement the disease prevention plan only after getting approval," the notification said.

All primary and middle schools as well as kindergartens should learn from the painful lesson of the recent unauthorized distribution of prescription medicine and enhance their management to ensure children's safety, the notification said.

The incident is more serious than originally believed, as an investigation showed that the number of children who got the unauthorized prescription medicine was more than double what was first reported.

Shaanxi Party chief Zhao Zhengyong, Shaanxi Governor Lou Qinjian and Xi'an Party chief Wei Minzhou all instructed their departments to handle the case properly.

On Monday, a number of parents in Xi'an, the provincial capital, went to the private Fengyun kindergarten and demanded to be told why drugs were given to their children.

"I wonder why they gave the harmful drug to my kid if she was not ill," said a mother surnamed Cheng, whose 5-year-old daughter attends the kindergarten.

The event drew the attention of the local government, which soon sent to the school a joint investigation team from the city's education, health and public security bureaus and the food and medicine administration.

The preliminary investigation showed that the private kindergarten, established in 2007, had illegally given guanidine hydrochloride to the children for four years. Kindergarten manager Zhao Baoying told the parents and investigation team that the kindergarten gave the students the medicine to keep them from catching cold.

But medical experts said that the drug is for treatment, not prevention.

The drug is used to treat viral influenza or herpes virus infections. Its side effects includes sweating, loss of appetite and low blood sugar.

Many parents complained that their children had some adverse effects to the medicine, including stomachaches, itchy skin and sleep hyperhidrosis, more commonly known as night sweats.

On Wednesday, police detained the kindergarten's owner, Sun Xuehong; Zhao, the manager; and the school physician, Huang Linxia. The investigation team found that Huang was not a qualified doctor and not allowed to give prescription drugs to patients.

The investigation team said it learned that the Fengyun kindergarten's 692 students weren't the only ones getting the drug. The Hongji Xincheng kindergarten, also owned by Sun, also gave the drug to its 763 students. Details of that school's alleged drug distribution are still being investigated.

The Hongji Xincheng kindergarten manager, surnamed Mei, and its deputy manager, surnamed Zhao, were also detained by police.

The city government has arranged to have all 1,455 children from the two kindergartens get free health examinations, and the local education authority has sent new managers and teachers to the two schools.