Tens of thousands march in Moscow anti-war protest but others back Crimean referendum

Boris Nemtsov, a former Russian deputy prime minister and opposition leader addresses demonstrators during a massive rally to oppose president Vladimir Putin's policies in Ukraine, in Moscow, Saturday, March 15, 2014. Large rival marches have taken place in Moscow over Kremlin-backed plans for Ukraine’s province of Crimea to break away and merge with Russia. More than 10,000 people turned out Saturday for a rally in the center of the city held to oppose what many demonstrators described as Russia’s invasion of the Crimean Peninsula. In a nearby location, a similar sized crowd voiced its support for Crimea’s ethnic Russian majority, who Moscow insists is at threat from an aggressively nationalist leadership now running Ukraine. (AP Photo/Alexander Zemlianichenko) (AP Photo/Alexander Zemlianichenko) (The Associated Press)

Demonstrators carrying Russian and Ukrainian flags march to oppose president Vladimir Putin's policies in Ukraine, in Moscow, Saturday, March 15, 2014. Large rival marches have taken place in Moscow over Kremlin-backed plans for Ukraine’s province of Crimea to break away and merge with Russia. More than 10,000 people turned out Saturday for a rally in the center of the city held to oppose what many demonstrators described as Russia’s invasion of the Crimean Peninsula. In a nearby location, a similar sized crowd voiced its support for Crimea’s ethnic Russian majority, who Moscow insists is at threat from an aggressively nationalist leadership now running Ukraine. (AP Photo/Alexander Zemlianichenko) (AP Photo/Alexander Zemlianichenko) (The Associated Press)

Tens of thousands have gathered in downtown Moscow in the largest anti-government demonstration since 2012, protesting against Sunday's Kremlin-backed referendum in Crimea on whether to break away from Ukraine and merge with Russia.

Demonstrators waved Russian and Ukrainian flags on Saturday while opposition activists — including the two members of the punk band Pussy Riot who served prison terms for an anti-government stunt — shouted "Say no to war!" and "Putin, go away!" from a stage.

Not far away near the Kremlin, several thousand people dressed in matching red costumes marched in formation to show their support for Russian intervention in the region.

Support for reclaiming Crimea, where a majority of residents speak Russian, has intensified amid relentless state television coverage of the region.