Vienna  - Drug abuse continues to rise in Afghanistan and western Asia, as opium trade remains a problem despite international efforts to curb production, a UN report released on Thursday said.

In its annual report, the International Narcotics Control Board (INCB) also warned that African countries were increasingly being used as hubs for trade in chemicals needed for making drugs.

Although Afghan poppy cultivation decreased by 19 per cent in 2008, the Vienna-based INCB said that "eradication efforts in Afghanistan are being hampered by lack of security, poor planning and inadequate equipment and funding."

Drug abuse even rose in some provinces where opium poppy is no longer cultivated, and heroin manufacturing increased as well. Of the population, 1.4 per cent are estimated to use poppy-based drugs.

Afghanistan's opium problem continues to affect the western Asian region, the INCB wrote. For example, at 2.8 per cent of the population, Iran has the world's highest abuse rate of opiates.

In Western Europe, Afghan heroin is increasingly being trafficked by train from Russia, Belarus, Poland and the Ukraine, the INCB wrote, noting that abuse of opiates was on the rise along that route.

The INCB called on Afghanistan and countries along trade routes to eliminate loopholes used by traffickers to ship so-called precursor substances, chemicals used for making heroin or other drugs.

Trade in precursor chemicals is also a growing problem in a number of African countries, according to the INCB, which monitors countries' adherence to international drug control treaties.

Criminal organizations were often posing as fake companies to order chemicals for making amphetamine-type stimulants including methamphetamine or ecstasy.

Numerous suspicious shipments from Africa had Mexico as a final destination, where methamphetamine production supplies the market in the United States, the report said.

As amphetamine abuse was on the rise in China, Malaysia and Vietnam, the INCB warned that the problem could spread to South Asia.

In cocaine trade, West Africa has become a shipment hub from Latin America to Europe, leading to "serious concerns that drug trafficking is undermining political, economic and and social structures."

Most South American countries reported increasing cocaine abuse. At 2.7 per cent of the population, Argentina had the highest rate, with 25 per cent of cocaine abusers aged 16 or younger. (dpa)