At least 18 children have died in Uzbekistan after consuming a medicinal syrup manufactured by Indian drugmaker Marion Biotech, according to the Uzbek Health Ministry.

The ministry said 18 out of 21 children who took the Doc-1 Max syrup while suffering from an acute respiratory disease died after consuming it. It is marketed on the company’s website as a treatment for cold and flu symptoms.

A batch of the syrup contained ethylene glycol, which the ministry said was a toxic substance. The syrup was imported into Uzbekistan by Quramax Medical, the ministry said in its statement released Tuesday.

It also said the syrup was given to children at home without a doctor’s prescription, either by their parents or on the advice of pharmacists, with doses that exceeded the standard dose for children.

It was not immediately clear whether all or any of the children had consumed the suspect batch or had consumed more than the standard dose, or both.

Marion Biotech, Quramax Medical and India’s Health Ministry did not immediately respond to a Reuters request seeking comment. An Indian government source told Reuters the Health Ministry was looking into the matter.

India had on Tuesday launched an inspection of some drug factories across the country to ensure high quality standards.