Some 300 people attended the rally Saturday, organizers told the Russian news agency Interfax, though security forces estimated some 150 demonstrators. Most of the rally participants were over 50 years old and wore pacifist symbols.

The anti-war event was organized by Russian Solidarnost movement, known for its opposition to President Vladimir Putin.

"I believe that this is not the last rally," Solidarnost representative Sergey Davidis told Interfax. "The subsequent ones will be much bigger."

Davidis added that "the nature of the matter is that consequences of Syria intervention will only get worse, and draw more attention as the crisis continues."

Solidarnost members and civil activists also criticized the perceived corruption within Russia's state structures.

The security forces detained one woman ahead of the event for holding up a sign with a slogan "Putin, you murderer, stop shaming Russia."

The rally in the Russian capital was marked by a notable police presence. In addition, a small group of government supporters approached the protesters chanting slogans in support of the Kremlin's policy.

Russia has been conducting airstrikes in Syria since late September, with the proclaimed goal of destroying "Islamic State" strongholds.

The US and other countries accuse Russia of targeting all opposition forces and acting solely in the interest of Syrian President Bashar al-Assad.

dj/bk (AFP, Interfax)