Opium trafficking provides the Taliban with much of its income

International and Afghan troops have killed 60 militants and made a record drugs haul in an operation in southern Afghanistan, the US military has said.

Its statement said the four-day attack targeted the town of Marja in Helmand province - a Taliban stronghold.

The troops seized 92 tonnes of opium poppy seeds and other drugs, "severely disrupting" a key narcotics centre and command hub of the insurgency.

The US denied reports that civilians were killed during the operation.

However, a spokesman for the Afghan defence ministry told the BBC that it was investigating the reports.

Taliban militants have so far not commented on the US statement.

Weapons seized

On Saturday, the US military said the joint operation focussed on Marja, south-west of the provincial capital of Lashkar Gah.

It said the troops targeted the town's bazaar, describing it as a key hub for militant and criminal operations.

The area was emptied of civilians overnight on Friday, before precision airstrikes were launched, the statement said.

The international and Afghan forces then seized the poppy seeds, along with tar opium, processed morphine, heroin and hashish.

Helmand is the main producer of Afghan opium, which accounts for more than 90% of the global supply.

The US military also said that a large amount of weapons and bomb-making equipment was seized during the operation.