Russian police searched opposition leaders' homes on Monday in morning raids intended to disrupt plans for a protest rally against President Vladimir Putin's rule and show he has lost patience with demonstrations that are undermining his authority.
The searches before Tuesday's rally were an aggressive turn after months of opposition rallies, signalling a tougher approach designed to crush dissent at the start of the former KGB spy's new six-year term as president.
Several leaders were also summoned for questioning on Tuesday about violence at a rally on the eve of Mr Putin's May 7 inauguration, almost certainly stopping them from attending the first big planned protest since he returned to the Kremlin.
Armed police stood guard as investigators searched the apartments of anti-corruption blogger Alexei Navalny, leftist leader Sergei Udaltsov and other opposition figures, rifling through rooms and seizing computer drives and disks.
"They practically cut out the door," Mr Navalny, one organiser of the protests sparked by allegations of fraud in a December parliamentary election won by Mr Putin's United Russia party, said on Twitter.
He tweeted that police had confiscated the electronics in his home "including discs with the children's photos".
After tolerating protests while seeking re-election, Mr Putin looks intent on carrying out promises to guarantee stability, even if critics say this could mean political and economic stagnation and a return to police tactics not seen since Soviet times when a knock on the door could lead to years of exile in a prison camp or even death under dictator Josef Stalin.
On Friday, he signed a law that increased fines, in some cases more than 100 fold, for violations of public order at street demonstrations, ignoring warnings from his human rights council that it was an unconstitutional infringement on the right to free assembly.
The federal Investigative Committee, Russia's main investigation agency, said it planned to conduct about 10 searches on Monday in connection with the criminal probe into violence against police at the earlier protest.
A former deputy prime minister, Boris Nemtsov, and Ksenia Sobchak, a TV presenter and socialite who has become a Putin critic despite her late father's close ties to the president 20 years ago before he rose to power, were also among those whose apartments were targeted, activists said.
Two dark-uniformed police officers armed with semiautomatic rifles guarded the entrance to Mr Navalny's modest, Soviet-built apartment building in a neighbourhood near Moscow's edge, allowing residents in and out but barring others.
Mr Navalny's lawyer was barred from his flat for hours, Ekho Moskvy radio said. His spokeswoman, Anna Veduta, said armed police also showed up at an office Mr Navalny uses, but they were unable to enter because there was nobody there.
Mr Udaltsov, head of the Left Front party, told reporters officers had confiscated computer drives, documents and discs, photographs of his children and flags for Tuesday's protest from his apartment.
"They rifled through everything, every wardrobe, in the toilet, in the refrigerator. They searched under the beds. Were they looking for our secrets?" he said outside the protest organisers' offices.
Opposition politician Sergei Mitrokhin said the raids were a sign that Putin was relying on oppressive measures to rein in dissent, rather than conducting political reforms.
"Putin has stopped even imitating democracy," Mr Mitrokhin, leader of the liberal Yabloko party, said on Ekho Moskvy.
Dozens expressed anger over the move on the Internet, which opposition activists and ordinary Russians have used to organise the protests, bypassing a compliant television media that is under tight state control.
"Vova is crazy," one Twitter user wrote, referring to Mr Putin by using the common nickname for Vladimir. Others messaged under the tag that translates as ' h ello1937' - a reference to the deadliest year of Soviet dictator Josef Stalin's repression.
"What we are witnessing today is in essence the year 1937," opposition activist Yevgenia Chirikova said. "It is an absolutely clear scenario in which the authorities scare the people."SUMMONED
Interfax news agency cited Investigative Committee spokesman Vladimir Markin as saying those whose homes were searched had been summoned to appear at the committee on Tuesday.
Mr Udaltsov said he and his wife had been summoned to appear at 11 a.m. (0700 GMT), an hour before the protest's scheduled start.
At an emergency meeting in a cramped Moscow office, activists confirmed that at least one other leader, Ilya Yashin, had received a summons.
Opposition leaders have permission for a march and rally in central Moscow, a test of their ability to maintain pressure on Mr Putin through protests despite the new law increasing fines for protests at which to as much as 300,000 roubles for participants and 1 million roubles for organisers.
In power since 2000, Mr Putin won a six-year presidential term in March despite the protests which have drawn tens of thousands of people to the streets, particularly middle-class city dwellers worried about economic and political stagnation.
Police largely left those protests alone but began to crack down after Mr Putin's election, beating protesters in clashes that broke out at a demonstration on the eve of his inauguration in May and chasing peaceful protesters around Moscow in the subsequent days and weeks, briefly detaining hundreds.
They have also detained 12 people on suspicion of responsibility for violence at the May 6 protest on charges that are punishable by jail terms of more than a year.
Opposition leaders including Mr Navalny and Mr Udaltsov have repeatedly been jailed for days over protests and fined small amounts, but have avoided more serious charges. The new law means they could be fined up to 1 million roubles for organising protests at which public order is deemed to have been violated.
© Thomson Reuters 2012