Afghan authorities say three members of the country's anti-narcotics squad have been wounded during a raid on a notorious opium and heroin bazaar near the border with Pakistan.

Local police say four suspected drug dealers were arrested during the operation by the Afghan Special Narcotics Force Monday in the town of Bahram Chah in Helmand province.

They say the forces also seized and burned about 1,000 kilograms of opium, and they discovered an underground bunker filled with heavy weapons that were later destroyed.

It was the squad's second raid on the bazaar in a week.  The first netted 75 kilograms of opium resin and one suspect.

Afghanistan is the world's largest producer of opium.  President Hamid Karzai has vowed to wage war on the drug trade.  Last year, he presented an eight-point plan to eradicate poppy production.

Some information for this report was provided by AFP and AP .