MOSCOW - Millions of Russians, from Kaliningrad in the west to Vladivostok in the Far East, voted on Sunday to elect a new president, with Prime Minister Vladimir Putin, a former president, the strong favorite. 

Four other candidates are running - Communist Party leader Gennady Zyuganov, the Liberal Democratic Party's Vladimir Zhirinovsky, Sergei Mironov from A Just Russia, and independent candidate Mikhail Prokhorov - for the six-year presidential term. 

Voting ended at 8 pm in each of Russia's nine time zones. Preliminary results were expected to be announced in the early hours on Monday. 

In the spring snow on Sunday morning in Moscow, voters lined up to cast their ballots. Gregory Mikhailovich, a construction worker, was the first in a long queue at a polling station in Moscow State University. 

"The vote is very important for every Russian. Otherwise there's no need to come here and do this," Mikhailovich, who returned to work after he cast his vote, said. 

"I hope the new leader improves our lives and our children's lives." 

With Putin, who held the presidency for two terms from 2000 to 2008, widely expected to secure more than half the vote and win directly in the first round, his supporters planned for early celebrations near Manezh Square on Sunday night. 

That is only part of 26 rallies pro-Kremlin youth movements plan to hold in Moscow between Sunday and Monday, according to the Komsomolskaya Pravda Daily. 

If Putin wins in the first round, he will be inaugurated president in early May, replacing the current office holder, Dmitry Medvedev. Putin has promised to appoint Medvedev prime minister. 

Authorities in the Russian capital mobilized 16,000 police officers, 14,000 volunteers, more than 4,000 guards and 2,000 police academy students for security on election day. 

More than 380,000 police officers were deployed for the event across Russia, the Interior Ministry said. 

Two webcams have been installed in each of the nearly 95,000 polling stations throughout Russia. The $478 million project was a core promise by Putin in the wake of protests against alleged fraud in Russia's parliamentary elections in December. 

"We have more than 90,000 transmission points for 200,000 cameras - never has anything like this been done in the whole world," Russia's communications minister Igor Shchyogolev said on Thursday. 

Some 600,000 people had registered on the vybory2012.ru website to monitor the voting process via the Internet, according to the chief of the Moscow municipal electoral commission, Valentin Gorbunov. 

In a pre-election televised address on Friday, Putin called on all voters to "make their deliberate choice" to "define Russia's destiny". 

Although there will be no street demonstration on election day, Moscow city hall has approved protests on Monday. While acknowledging that protests were expected no matter how the election turns out, Putin on Friday said all Russians must unite together and "work smoothly and constructively, without shocks or revolutions". 

Putin seeks to transform Russia toward a more modern, rule-of-law based society. He also aims for six-to-seven percent annual growth in the economy to put Russia, now ranked 11th, into the top five by the end of this decade. 

But this will not be easy. 

Parliamentary elections in December saw the ruling United Russia Party narrowly securing a majority - with a sharp drop in seats - in the new State Duma. The protests against alleged fraud in those elections have continued. 

Nonetheless, Mikhail Dmitriev, a senior government adviser and former first deputy minister of economic development and trade, and earlier, of labor and social development, said the protesters "simply failed to formulate any substantive political agenda at the federal level". 

"They cannot organize into a movement which can help formulate policies," he said of the protesters who mostly rely on online social networks for mobilization. Putin made similar remarks on Thursday, saying that the protesters lack "constructive proposals". 

But observers say Putin will need to come up with reconciliatory measures to engage the opposition and move toward institutional reform. There are signs he will do this. On Thursday Putin called the protests "a very good experience for Russia" and said the protesters "make us think, search for solutions and communicate with society". 

Putin, already seeing his support decline in major cities, now has to curb discontent from further penetrating into his major power bases throughout the countryside and industrial towns, Dmitriev said. 

His public approval rating has fallen from 85 percent in mid-2008 to between 63 and 66 percent this month, figures from independent pollster Levada Center showed. 

The ability to curb inflation, create jobs and improve social services - an increasingly costly endeavor - will test Putin's image among his most loyal supporters, said Vladimir Frolov, president of a government relations firm. 

Meanwhile, public frustration with poor governance and corruption, which Putin repeatedly identified as a major social ill in Russia, could only be eased with "very serious changes in the political system", Dmitriev said. 

Change is essential for Putin, for much of the Russian public now see him as a "very successful leader of the past" and hardly associate any new achievement with him, Dmitriev said. 

But the core task at hand - reconciling the interests of the majority of Russian society with those of vested groups - is "very hard", he said. 

Putin himself on Friday admitted that he does not yet have a formula to restore social justice destroyed during the process of privatization in the 1990s. 

Other, more immediate changes may include radical plans to reshuffle, rebrand, or even dissolve the widely discredited United Russia, which Putin in December called "a major cornerstone of our strategic stability". 

Sergei Markov, a Kremlin-affiliated analyst and former United Russia Duma deputy, was earlier quoted by The Moscow Times as saying that there are indeed plans to dissolve the party. Meanwhile, Alexander Vorobyov, head of United Russia's Duma faction, last month tweeted that only with "change and renewals" can the party retain its leadership. 

In any event, the popularity of United Russia's centralist position, which has dominated Russian politics for years, is fast depleting, Dmitriev said. 

"Now, the Russian population is getting more polarized. There is almost no centralist electorate left. Most likely, we'll get competition between the leftist parties, which have a good chance of winning a parliamentary majority (in the future), and more right-wing parties, which have not yet emerged in Russia but may emerge soon," he said. 

Mikhailovich, the construction worker, said all Russians should "leave political conflicts to politics". 

"The people should unite for our country," he said. 

Xing Guangcheng, a researcher on Russian studies at the Chinese Academy of Social Sciences, said there is "little doubt" that Putin will be elected, but he will face major challenges. 

One of the biggest challenges will be to adjust Russia's economic development strategy and economic structure, which sill has a long way to go, Xing said. Corruption is another serious problem that Putin will be confronted with, he said. 

On Russia's future foreign policy, Xing said Putin is unlikely to make any strategic changes as Russia's foreign policy has been "relatively clearly outlined during the Medvedev-Putin tandem". 

Russia will also maintain its well-developed "comprehensive strategic partnership of cooperation" with China. 

Cheng Guangjin in Beijing contributed to this story.