Russian and US agents have taken part in a joint operation to destroy drug laboratories in Afghanistan, the head of Russia's drug control agency says.
More than a tonne of heroin and opium was seized during the raids, which took place on Thursday close to the border with Pakistan, Viktor Ivanov announced.
Mr Ivanov said the haul had a street value of $250m (£157m) and was believed to have been destined for Central Asia.
Correspondents say it is the first time there has been such a joint operation.
Russian officials have in the past accused coalition forces in Afghanistan of doing "next to nothing" to tackle drug production, and thereby helping to sustain the estimated 2.5 million heroin addicts in Russia alone.
Much of the heroin enters the territory of the former Soviet Union through Afghanistan's northern borders with Tajikistan and Turkmenistan.
It then travels westwards across Kazakhstan, before entering the central and Ural regions of Russia, where there are large numbers of addicts.
Mr Ivanov said the operation involved about 70 personnel from both countries - including four Russian counter-narcotics agents - backed up by attack helicopters.
They were on the ground for several hours, destroying a "major hub" for the production of heroin, located in a mountainous area about 5km (three miles) from the Pakistani border near the eastern city of Jalalabad, he said.
Along with 932kg (2,055lb) of high-grade heroin and 156kg (345lb) of morphine, a large amount of technical equipment was destroyed.
Mr Ivanov said the raids were based on intelligence Russia had shared with the US, and that he wanted to increase co-operation in the fight against drug trafficking.
"We are ready and we want to send an additional number of our officers for posting to the international information centres functioning in Kabul, Bagram and Kandahar," he said.
The BBC's Richard Galpin in Moscow says the joint operation is yet another sign of Russia's growing involvement in Afghanistan.
Since the two countries decided to reset their relations, Russia has allowed its territory to be used as a supply route for US and Nato forces in Afghanistan, our correspondent says.
It is now also offering to provide military equipment for the Afghan army.