(Reuters) - Vladimir Putin won a resounding victory in Russia's presidential election on Sunday, exit polls showed, securing a new six-year term in the Kremlin and a mandate to deal with opposition protests after a vote that opponents said was marred by fraud.
Two television exit polls, released after voting ended at 1700 GMT, forecast the former KGB spy would win 59.3 and 58.3 percent of the votes, enough to make a runoff against the second-placed candidate unnecessary.
His nearest rival, communist Gennady Zyuganov, fell short of 20 percent in both polls.
Putin's opponents said voting in many parts of the vast country was skewed to help him return to the presidency after four years as prime minister and vowed to step up the biggest protests since he rose to power 12 years ago.
But although they portray him as an authoritarian ruler who is out of touch, his victory had not been in any doubt.
The main challenge for Putin, credited by many Russians credit with rebuilding the country's image and overseeing an economic boom, was to win outright in the first round.
"I think the elections will be legitimate, fair, and Putin will win in the first round, unless the court rules otherwise," Putin's spokesman, Dmitry Peskov, was shown saying on Internet and cable television channel TV Dozhd before voting ended.
Putin was likely to portray the victory as strong backing against the opposition protesters, although he has promised not to crack down on them.
He is also expected to return to the Kremlin with tough fighting talk against the West, a trademark of his first presidency and election campaign.
Some voters expressed anger at being offered no real choice in a vote pitting Putin against four others - communist Zyuganov, nationalist Vladimir Zhirinovsky, ex-parliamentary speaker Sergei Mironov and billionaire Mikhail Prokhorov.
Others said Putin, 59, who has portrayed himself as a man of action and guardian of stability, was the tough national leader the world's biggest country and energy producer needed.
"I voted for Putin because he was a good president and our children were looked after and that's all. That's how I feel," said Maria Fedotova, a 92-year-old grandmother wrapped up in fur coat and hat, flanked by relatives.
Putin has remained Russia's dominant leader and its most popular politician since stepping aside in 2008 to make way for his ally, Dmitry Medvedev, because he was barred from a third straight term by the constitution.
But some voters are tired of his macho antics, such as horse riding bare chested, and a system that concentrates power in his hands. They fear he could win two more terms, ruling until 2024 - almost as long as Soviet dictator Josef Stalin.
Vote monitors from the opposition and bloggers posted allegations of election rigging across the country of 143 million. Golos, an independent monitoring group, said it had registered at least 2,283 reports of violations nationwide.
An Interior Ministry spokesman denied there had been any major violations. Election officials also dismissed reports of widespread fraud in a parliamentary election on December 4 which triggered the opposition protests.
Thousands of opposition activists as well as an international observer mission were also monitoring the polls.
The opposition protests were sparked by the disputed December 4 election, but anger was focused at Putin, who bungled the September 24 announcement of his presidential bid by appearing simply to inform Russians that he would rule for another six years.
Alexei Navalny, a prominent opposition leader and anti-corruption blogger, said before the vote that Putin's election could not be legitimate and called for more protests, including tent camps in Moscow.
(Writing by Timothy Heritage, Editing by Douglas Busvine)