Russians voted on Sunday in parliamentary polls seen as a test of Vladimir Putin's personal authority ahead of a planned return to the presidency, and an electoral watchdog complained of 'massive cyber attacks' on a website alleging violations.

Putin remains by far the most popular politician in the country but there are some signs Russians may be wearying of his cultivated strong man image. The 59-year-old ex-spy looked stern and said only that he hoped for good results for his United Russia party as he walked past supporters to vote in Moscow.

I will vote for Putin. Everything he gets involved in, he manages well, Father Vasily, 61, a bespectacled and white-bearded monk from a nearby monastery said. It's too early for a new generation. They will be in charge another 20 years. We are Russians, we are Asians, we need a strong leadership.

A Western-financed electoral watchdog and two liberal media outlets said their sites had been shut down by hackers intent on silencing allegations of violations. Sites belonging to the Ekho Moskvy radio station, online news portal Slon.ru and the watchdog Golos went down at around 8 a.m.

Massive cyber attacks are taking place on the sites of Golos and the map showing violations, Golos said on twitter.

Golos said it was excluded from several polling booths in the Siberian Tomsk region. Moscow prosecutors launched an investigation last week into Golos' activities after lawmakers objected to its Western financing. On Saturday, customs officers held Golos's director for 12 hours at a Moscow airport.

Washington said it was concerned by a pattern of harassment against the watchdog.

Ekho Moskvy editor-in-chief Alexei Venediktov wrote on Twitter: It is obvious the election day attack on the (radio) site is part of an attempt to prevent publishing information about violations.

President Dmitry Medvedev, who is stepping aside in March so that Putin can return to the presidency, has dismissed talk of electoral fraud. Neither the general prosecutor's office nor the Central Election Commission could be reached for comment.

Some voters said they would vote for Just Russia, which calls itself 'new socialist', or the Communists, who retain support largely among poorer citizens two decades after the collapse of the Soviet Union and the advent of a free market system.

Communist Party leader Gennady Zyuganov, voting at a cultural centre decked with Soviet-style hammer and sickle flags, said there appeared to be election violations in several of Russia's 93 regions spanning 9,000 Km (5,600 miles).

I just spoke to our people in the Siberia and the Far East and the situation is very worrying, he said.

Polls show Putin's party is likely to win a majority but less than the 315 seats it currently has in the 450-seat lower house of parliament, known as the Duma.

If Putin's party gets less than two-thirds of seats, it would be stripped of its so called constitutional majority which allows it to change the constitution and even approve the impeachment of the president.

PUTIN'S PARTY

supporters say Putin saved Russia during his 2000-2008 presidency, restoring Kremlin control over sprawling regions and reviving an economy mired in post-Soviet chaos.

His use of military force to crush a rebellion in the southern Muslim region of Chechnya also won him broad support.

Opposition parties say the election was unfair from the start because of authorities' support for United Russia with cash and television air time.

Putin has no serious personal rivals as Russia's leader. He remains the ultimate arbiter between the clans which control the world's biggest energy producer.

But his party has had to fight against opponents who have branded it a collection of swindlers and thieves and combat a growing sense of unease among voters at Putin's grip on power.

I shall not vote. I shall cross out all the parties on the list and write: 'Down with the party of swindlers and thieves,' said Nikolai Markovtsev, an independent deputy in the Vladivostok city legislature on the Pacific seaboard.

These are not elections: this is sacrilege, he said, adding that the biggest liberal opposition bloc had been barred from the vote by the authorities.

Opponents say Putin has crafted a brittle political system which excludes independent voices and that Russians are growing tired of Putin's swaggering image.

Putin is almost certain to win the March 4 presidential election but signs of disenchantment are worrying for the Kremlin's political managers.

Sports fans booed and whistled at Putin at a recent Moscow martial arts fight -- an exceptional event in a country inclined to show respect and restraint towards leaders.

(Writing by Guy Faulconbridge; Editing by Ralph Boulton)

($1 = 30.8947 Russian roubles)