Washington - Worldwide production of cocaine and heroin dropped in 2008, with the sharpest reductions in Colombia and Afghanistan, the United Nations said in a report Wednesday.

Cultivation of opium poppies - from which heroin is derived - fell by 19 per cent in Afghanistan, which is the largest producer of the drug. In Colombia, the largest exporter of cocaine, coca production declined by 18 per cent, the report said.

Antonio Maria Costa, director of the UN Office on Drugs and Crime, said that increases in seizure levels combined with higher prices and unstable consumption markets have contributed to the drop in cocaine supplies.

"The 50-billion-dollar global cocaine market is undergoing seismic shifts," Costa said, noting that the trend has likely contributed to the "gruesome upsurge" of violence as cartels compete in shrinking markets.

The Vienna-based Office on Drugs and Crime released its report at a press conference in Washington. The UN report comes as US and NATO forces have intensified work with Afghan authorities to crack down on poppy production. Afghanistan produces 93 per cent of the world's opiates, with Europe serving as the largest destination for the drug.

The report cited a decrease in demand for cocaine in the United States, which is the largest importer of the illicit drug.

While noting the markets for cannabis, cocaine and heroin remained largely flat or declined, the United Nations noted an increase, mostly in developing countries, in the production and consumption of synthetic drugs like amphetamines, methamphetamines and ecstasy.

In the Middle East, the use of the amphetamine Captagon "sky- rocketed." Seizures of amphetamines in Saudi Arabia accounted for nearly one third of global seizures for these drugs.

In South-East Asia, industrial-scale laboratories continued to turn out methamphetamines, with increasing manufacture in Malaysia and Indonesia, the report said.(dpa)