Authorities have been alerted to a new, harmful narcotic-like cocktail taken among high-school students who can easily buy the ingredients and search for its formula on the internet.
The drug is called ya pro (from the drug "procodyl" used to make it), and it is a mix of soft drinks, cough syrup, muscle relaxants and cold medicines. The last three ingredients can be bought over the counter at chemists.
A high dose of these four drugs will affect the brain, giving an effect similar to taking narcotics.
"What is seriously worrying is students can easily search for the mix from Google," said Thi Bhawangkanantha, head of the Child Protection Centre at the Office of the Basic Education Commission (OBEC), adding some drug stores are selling the mix.
Mr Thi said his office will tell drugstore operators to be more careful when selling the ingredients and step up truancy patrols.