The deputy head of Russia's drug control agency says a flood of cheap heroin from Afghanistan is turning children into addicts.
Opium is the most lucrative crop for Afghan farmers
"A heroin attack from the south has become the most acute problem for us," said Alexander Mikhailov.
He blamed the US-led military action in Afghanistan for aggravating the problem, by failing to tackle opium production after toppling the Taleban government.
He said heroin use in Russia had risen 23-fold in five years, and that children were now among those most at risk of falling prey to addiction.
"Drugs have already become a part of youth culture here," Mr Mikhailov said.
"We previously said that the most dangerous age for acquiring a drug habit was between 18 and 25, but now we talk about the age between 11 and 14."
The Russian drug control agency was created by President Vladimir Putin earlier this year.
He named Viktor Cherkesov, a trusted ally from his days in the KGB, to head the force of 46,000.
RUSSIAN DRUG USE
Heroin: up 23 times since 1998
Amphetamines: up 20 times
Cocaine: up 10 times
500,000 registered addicts
Four million drug users
Mr Mikhailov said Russia had between three and four million drug users, out of a population of about 145.5 million.
Russian officials seized 2.9 metric tons of drugs in the first half of this year, half of it heroin, he added.
Russia's largest-ever drugs haul - a lorry-load of 420 kilograms of heroin - was made shortly after the new agency started work.
Mr Mikhailov said corrupt officials had helped to encourage the drug flow, citing cases in Rostov and Yekaterinburg regions where police were found to be involved in the trade.
But he also said the US had "stirred up a hornet's nest" in Afghanistan, leaving Russia to face an epidemic of addiction.