Heroin smoking is also on the rise and cannabis with high tetrahydrocannabinol (THC) content has become popular in illicit drug markets, particularly in North America, says the report which was released here and in 30 other cities around the world on Tuesday.

Benzodiazepine abuse has increased sharply in Europe and other developed countries, where some doctors are prescribing the medication over long periods of time for a questionable array of symptoms.

The Board has urged the Governments concerned to impress upon doctors that these drugs must be used more sensibly.

The abuse of amphetamine type stimulants, especially ` Ecstacy', hasspread in South America, particularly in Argentina, Brazil, Chile and Uruguay, as well as in the former Soviet Union and West Asian countries.

The use of psychotropic substances and polydrugs has recently grown in South Asia, which lack funds to enforce national drug control laws or monitor domestic channels for pharmaceutical products.

Although cannabis has been regularly eradicated in India, Nepal and Sri Lanka, the plant is still being grown illegally, mainly for use in South Asia. A new concern in the region, especially in urban centres, is a link between the spread of Acquired Immune Deficiency Syndrome (AIDS) and drug abuse by injection, which is common in the region.

Most of the opiates seized in 1998 in India came from south-west Asia. The total amount of heroin seized in 1997 was about one tonne, with the largest part coming from Kabul and first brought to Peshawar in Pakistan.