In July, Malaysia announced that in order to curb the spread of what it called the "Black Metal" cult, foreign groups would have to submit videotapes of their concerts to the government before being allowed to perform in the country.

Malaysia's Prime Minister, Mahathir Mohamad, has criticised both rap and heavy metal music for corrupting the morals of Malaysia's population.

State radio has also been ordered to play less heavy metal music.

Mr Hanafi told the Associated Press that the state has detained about 700 teenagers, mostly students, since the clampdown started.

"Black Metal" members are accused of sacrificing animals, drinking blood, smoking cannabis and desecrating religious texts, such as the Koran.

Herbal stimulants

The authorities say they use heavy metal music to attract new recruits.

Some Kedah school officials have already started strip-searching students to check for tattoos, crucifixes worn upside-down or other alleged signs of belonging to the "Black Metal" cult.

The Scorpions were vetted before being allowed to play in Malaysia

Cult members have also been offered counselling and rehabilitation.

The herbal medicine has been developed by a private company to treat drug addicts and Mr Fadzil said the unnamed drug had been "found to be effective in stimulating their thinking".

He said it would be given to pupils at 15 schools most affected by the cult.