Russian officials are using grey areas in the law to clamp down on Internet news sites in what campaigners fear could signal an attack on one of the few media outside the control of the Kremlin and its supporters.

A loophole in the law allows authorities to treat Web sites as fully fledged publications—with all the responsibilities that go with that status - and then use these requirements to take court action against them.

Two local Web sites have been punished for failing to register as media outlets. Thousands of other sites are unaffected but many in the Internet community say the court actions could be the start of a trend.

And they say blogs—the most vibrant and least regulated part of Russian cyberspace—could be targeted next if officials object to off-the-cuff comments posted online.

"It is a situation which reminds me of Soviet times when the KGB jailed people for telling jokes," Oleg Panfilov, a freedom of speech campaigner who heads the Centre for Extreme Journalism, told Reuters. "It's bureaucrats taking liberties."

Most of Russia's biggest conventional media are already controlled by the state or by pro-Kremlin businessmen. Many politically-active Russians therefore see the Internet as the only free forum for debate.

Russia's state media and cultural heritage watchdog denied any crackdown on free speech, saying it was a matter for the local courts which took action against the Web sites.

"Internet-related issues are not regulated properly in the legal sense. Therefore we rely to a certain extent on the way judges interpret the law," said watchdog spokesman Yevgeny Strelchik.

The most prominent case was last December when a judge in the Siberian region of Khakassia ordered the Novy Fokus Internet publication to close down.

The court's argument was that the publication had failed to register with the authorities as a media outlet.

Novy Fokus said it was not required to register and was being singled out by local bureaucrats for its outspoken reporting on local politics.

"A fierce and blatant elimination of independent journalism is under way in Khakassia," the editor, Mikhail Afanasyev, wrote on his Web site after the original decision.

On appeal, a city court overruled the decision to close down Novy Fokus but left in force a fine of 20,000 roubles ($769). The site is back after a four-month absence.

The differences arose because Russian law says nothing about whether Internet news sites are required to register as media outlets, legal specialists say. That left the court to interpret the law itself.

In a similar case, the Zyryanskaya Zhizn Web site, based in the Komi region in Northwestern Russia, was fined for failing to register as a media outlet, and prosecutors have applied to have it shut down.

Novy Fokus was defended in its case by Irina Khrunova, a high-profile civil rights lawyer.

She said it was a test case which could set a precendent not just for Internet news sites like Novy Fokus but also for blogs which are proliferating in Russia.

Russians are the second-largest group of users represented on the popular U.S.-based blog hosting site www.livejournal.com. Their blogs often feature political debates and advertise protests by opposition groups.

"You can trawl through different blogs and chats and you can see this issue (the Novy Fokus case) was discussed a lot by computer buffs," Khrunova said.

"People were pretty much knocked sideways because they understood this decision could at some point have an impact on them."