MOSCOW -- There were "serious problems" in the vote that returned Vladimir Putin to the Russian presidency, the head of the major international election observer mission said Monday, adding fuel to an opposition testing its strength with plans for a massive protest rally.
Putin rolled to victory as expected Sunday to return to the Kremlin and keep his hold on power for six more years, but opponents claim the voting was rigged. A rally has been set for Monday evening on Moscow's Pushkin Square, one of the central city's most iconic locations, with news reports say some 12,000 police and troops will be on duty to ensure order.
A brief synopsis by the Organization for Security and Cooperation in Europe observer mission did not address complaints of widespread cases of people casting multiple ballots, but said the election "was assessed negatively" in almost a third of polling stations observers visited.
"There was no real competition, and abuse of government resources ensured that the ultimate winner of the election was never in doubt," said Tonino Picula, the head of the short-term observer mission.
The Central Elections Commission says the prime minister, who was president in 2000-2008, got more than 63 percent of the nationwide vote. The independent Russian elections watchdog Golos says incomplete reports from its observers of individual polling station counts indicate he hovered perilously close to the 50-percent mark needed for a first-round victory.
"It's one pixel away from a second round," said Golos' Roman Udot.
Putin claimed victory Sunday night when fewer than a quarter of the votes had been counted, his eyes brimming with tears. He defiantly proclaimed just outside the Kremlin walls before a sea of supporters that they had triumphed over opponents intent on "destroying Russia's statehood and usurping power."
Putin's win was never in doubt as he faced a weak slate of Kremlin-approved candidates and many across the vast country still see him as a guarantor of stability and the defender of a strong Russia against a hostile world, an image he has carefully cultivated during 12 years in power.
The OSCE observers' conclusions may have significant bearing on whether Russia's opposition forces will be able to maintain the protests of the last three months, the largest public show of anger in post-Soviet Russia. Opposition demonstrations previously had been severely limited by officials, and any unauthorized gatherings were harshly dispersed by police.
Officials gave permission for the massive rallies, which attracted tens of thousands, but it was not clear if the tolerance would continue in the post-election period.
On Monday, outgoing President Dmitry Medvedev ordered the Justice Ministry to present its explanation for last year's rejection of registration for the People's Freedom Party, an organization led by some of the opposition's most prominent figures.
He also ordered the prosecutor-general to re-examine the legality of the conviction of imprisoned former oil tycoon Mikhail Khodorkovsky and more than 30 others regarded by the opposition as political prisoners.
Some observers saw the move as a maneuver to try to soothe protesters.
Medvedev, "it appears, is trying in advance to break the protest wave, " political analyst Pavel Svyatenkov was quoted as saying by the ITAR-Tass news agency.
At least one opposition figured vowed that strategy wouldn't work.
In general, this step can be welcomed. But I don't think it should stop the criticism of authorities," Left Front leader Sergei Udaltsov told the state news agency RIA Novosti.
The West can expect Putin to continue the tough policies he has pursued even as prime minister, including opposing U.S. plans to build a missile shield in Europe and resisting international military intervention in Syria.
Communist Party candidate Gennady Zyuganov was a distant second in the election, followed by Mikhail Prokhorov, the billionaire owner of the New Jersey Nets basketball team whose candidacy was approved by the Kremlin in what was seen as an effort to channel some of the protest sentiment.
The clownish nationalist Vladimir Zhirinovsky and socialist Sergei Mironov trailed behind. The leader of the liberal opposition Yabloko party was barred from the race.
Associated Press writer Mansur Mirovalev in Moscow contributed to this report.