Russian deputy Foreign Minister Mikhail Bogdanov arrived in Tehran on Monday to discuss the crisis in mutual ally Syria with Iranian officials, Fars news agency reported.

"Mikhail Bogdanov, deputy foreign minister for Middle East and President Vladimir Putin's special representative arrived in Tehran at the invitation of his counterpart Hossein Amir Abdolahian to discuss regional issues and Syria," Fars said.

The ambassadors to Lebanon of the five permanent United Nations Security Council members held talks on Monday with President Michel Suleiman on the current security situation in Lebanon.

U.N. Special Coordinator for Lebanon Derek Plumbly said after the meeting that the five countries support the president's efforts to ease the tensions and put an end to the security chaos.

Russian troops on Sunday reported killing 49 militants in a massive security sweep that followed angry comments from President Vladimir Putin about raging violence in the troubled North Caucasus.

The National Anti-Terror Committee said the operation was conducted across several republics of the volatile Muslim region and resulted the removal of some of the most "odious" guerrilla commanders and their followers.

Russia's opposition went online Saturday to vote for new leaders to spearhead the drive against Vladimir Putin and regain the momentum lost since his thumping return to the presidency in May.

But hacking scuppered voting in the early hours while nearly a dozen police vans surrounded the one site in Moscow where Putin's foes could get help using computers to vote -- a security measure they saw as a form of pressure.

An opposition member of Russia's parliament claimed on Saturday that a Russian anti-Putin activist has been kidnapped from the United Nations refugee office in Ukraine.

The activist, Leonid Razvozzhaev, is being sought by a Russian committee inquiring into "preparation for the organisation of mass riots."

Russia's President Vladimir Putin on Wednesday defended its arms trade against criticisms over its dealings with Syria, insisting only the United Nations could dictate restrictions on arms sales.

Putin defended Russia's right to trade weapons with whomever it wanted, without mentioning Syria but in an apparent reaction to recent attacks from the West over supplies to Syrian President Bashar Assad's regime.

A senior U.S. official will hold talks in Ankara on Tuesday on a range of issues including the Syrian crisis amid heightened tensions between Ankara and Damascus, an embassy spokesman said.

"We continue to consult with our partners in the region including Turkey on a variety of issues related to Syria," U.S. embassy spokesman in Ankara T.J. Grubisha told AFP.

Turkish Prime Minister Recep Tayyip Erdogan reiterated Monday that the cargo Ankara confiscated from an intercepted Syrian plane contained weapons, shrugging off Russian claims that the plane carried legal radar equipment.

"It is beyond any doubt that the cargo is war equipment," Erdogan told reporters in Ankara.

The pro-Kremlin candidate steamrolled to victory Monday in a poll on the outskirts of Moscow that had been seen by the opposition as a chance to lodge a high-profile presence near the seat of Russian power.

The Khimki District vote on the northwestern edge of the capital was one of a slate held Sunday across Russia for the first time since President Vladimir Putin was overwhelmingly swept to power for a third term in March.

The Syrian plane intercepted by Turkey this week on a flight from Moscow was carrying a legal cargo of radar equipment, Russian Foreign Minister Sergei Lavrov said on Friday.

"This cargo is electrical technical equipment for radar stations, this is dual-purpose equipment but is not forbidden by any international conventions," Lavrov said in the Russian government's first public remarks about the nature of the cargo.