Photo released by Afghan Interior Ministry shows sacks of hashish found in province of Kandahar, 11 Jun 2008

Afghan and U.S. officials say Afghan troops have seized almost 237 tons of hashish, dealing a severe blow to Taliban insurgents who profit from the drug trade.

Once exported, the drugs would have been worth an estimated $400 million. The commander of NATO forces in Afghanistan, U.S. General David McKiernan, said Wednesday, of that amount, about $14 million would have gone to Taliban insurgents.

He said the seizure has "seriously crippled" the Taliban's ability to purchase weapons and threaten the Afghan people.

Officials say the hashish - which weighed as much as 30 of London's double-decker buses - had been buried in trenches in the Spin Boldak region of Kandahar province in southern Afghanistan.

Afghan counter-narcotics police set fire to the trenches to destroy the hashish.

U.S. and Afghan officials say the find may be the world's biggest, single seizure of illegal drugs.

Officials say the operation also resulted in the arrest of multiple drug dealers, including some from Iran.

General McKiernan congratulated the Afghan government on the operation and promised continued support and training.

Afghan officials also reported success in another counter-narcotics operation.

The Interior Ministry said police in Helmand province seized more than 5,000 kilograms of opium, worth about $30 million.

Meanwhile, the U.N. Security Council today called on countries to do a better job of regulating chemicals that Afghan drug lords need to produce heroin.

The council voted unanimously in favor of a resolution asking for better compliance with existing international treaties.