Heroin has become a national pandemic, with the number of drug users soaring 20 times over the past 20 years, Federal Drug Control Service chief Viktor Ivanov said Wednesday.

"We have every reason to assert that Afghan heroin has become a national problem for Russia," Ivanov said at a news conference, Interfax reported.

He estimated that up to 2.5 million Russians are drug users, 90 percent of whom are addicted to heroin.

He said more than 24,000 people are registered as drug users in Moscow, but the real number could be 10 times higher.

Federal Drug Control Service officials trumpeted their efforts to crack down on drugs at the news conference. Moscow police seized 338 kilograms of illegal drugs, including 240 kilograms of heroin, last year, said one official, Vyacheslav Davydov. He did not provide comparative figures.

Davydov said 856 foreigners were arrested for drug-related crimes, a 30 percent increase from 2008. Eighty percent of the detainees were from Central Asia or the Caucasus, and 20 percent were repeat offenders, he said.

Officials said the drug control agency planned to unveil a new strategy to fight drugs soon.

Davydov, meanwhile, complained that the Internet complicated the agency's work because it provides easy access to information on how to prepare and distribute drugs.

He also said drug traffickers were growing more sophisticated and described how difficult they were to track.

"One person handles the so-called 'traceless' drug stashing. It could be in a cigarette pack or behind a radiator in an apartment entrance. Finding this stash is extremely difficult. Another connects the client and the dealer, a third collects the money and sends it electronically or through money transfers like Western Union," Davydov said.

Ivanov reiterated earlier calls for a crackdown on Afghanistan's heroin production, noting that the country produces twice as much heroin as was produced globally 10 years ago and urging drastic steps, including UN-backed measures.