Russian police arrested dozens of activists, including opposition leader Boris Nemtsov, to stop a new protest alleging that elections were rigged in favor of Vladimir Putin's ruling party.

Helmeted riot police and interior ministry troops deployed in force for the rally in central Moscow which was held after an unusually large thousands-strong protest on Monday startled the authorities.

President Dmitry Medvedev on Tuesday warned the West against criticizing Russia's political system after OSCE-led observers said the elections were slanted in favor of ruling party United Russia.

"If they watch over the elections, the violations -- that is one thing," RIA Novosti quoted Medvedev as saying. "But the question of what the political systems looks like -- that is none of their business."

Russia has sent interior ministry troops to Moscow and increased the alert level of security forces after a protest of thousands of people opposing Vladimir Putin, officials said on Tuesday.

"They (the troops) have just one aim -- to ensure the security of the citizens," interior ministry forces spokesman Colonel Vasily Panchenkov told the Interfax news agency while a police spokesman said the security forces were now on a "heightened regime" of alert.

Russia is downgrading its relations with the Gulf state of Qatar following an airport attack on its ambassador, the foreign ministry said on Monday.

The ministry said Moscow's ambassador to Doha "was attacked by security and customs personnel" who were trying to strip him of his diplomatic bag.

The ruling party of Vladimir Putin Monday won Russia's parliamentary elections but with a sharply reduced majority, in a blow for the Russian strongman ahead of his planned return to the Kremlin in 2012.

United Russia is set to obtain 238 seats in the 450-seat State Duma, down sharply from the 315 seats it won in the last polls in 2007, election commission chief Vladimir Churov told reporters citing results from 96 percent of polling stations.

Russians voted Sunday in elections set to see Vladimir Putin's ruling party win a reduced majority in parliament, amid claims the authorities were engaging in foul play to ensure it maintained dominance.

Russia's main independent vote monitors have been denounced and harassed by the authorities ahead of the polls while several opposition news websites were the victims of an apparent mass hacking attack on polling day.

Russians prepared Saturday for parliamentary elections amid dwindling support for the ruling United Russia party and unprecedented pressure on election observers.

Voting in the world's largest country will begin at 2000 GMT Saturday in the Russian Far East regions and end 21 hours later when polling stations close at 1700 GMT Sunday in the exclave of Kaliningrad wedged between Poland and Lithuania.

Russia on Friday lambasted the U.N. Human Rights Council's findings of "gross violations" by Syria as "unacceptable" and warned against using them as a pretext for military action.

"The positions (adopted) in the document, which include the veiled hint of the possibility of foreign military intervention under the pretext of defending the Syrian people, are unacceptable to the Russian side," the foreign ministry said in a statement.

Amnesty International and rights activists on Wednesday called on the U.N. Security Council to refer the Syrian government's deadly crackdown on protests to the International Criminal Court.

A Syrian activist forced into exile by President Bashar Assad's government said there has to be "regime change" in the country, but with no foreign intervention.

A relic said to have belonged to the Virgin Mary left Russia Monday after a tour that saw it worshipped by three million people in a potent display of the power of the Russian Orthodox Church.

The Belt of the Virgin Mary attracted a million people in Moscow alone, inspiring them to queue in a five-kilometer (three-mile) line for up to 26 hours in hope of touching the silver chest holding the relic and receiving a miracle.