London  - British and Afghan troops have seized heroin and drug-making chemicals in southern Afghanistan with a street value of more than 50 million pounds (71 million dollars), Defence Secretary John Hutton said Wednesday.

Some 700 troops were involved in Operation Diesel, as the joint swoop on four drug factories in Helmand province was codenamed. It took place between February 6 and
11, Hutton revealed.

Facilities for making improvised bombs had also been disrupted.

"Operation Diesel was a clinical precision strike, supported by strong intelligence, which has had a powerful disruptive effect on known insurgent and narcotics networks in the area," Brigadier Gordon Messenger of the Royal Marines said.

"The success of the operation is a significant boost to the Afghan authorities in their fight against the drugs trade." (dpa)