Thousands of communists rallied in towns across Russia on Saturday against Nato plans to establish a transit base in Ulyanovsk.
The largest rally was staged in Moscow's Pushkinskaya Square, where about 2,000 people waving red flags and banners slammed the Putin government's "betrayal of national interests."
Communist Party general secretary Gennady Zyuganov attacked Nato's plan to "occupy the Volga," predicting that the base at Ulyanovsk airport would become "a major drug trafficking point.
"An ulcer is forming in the centre of Russia, which will not only be a transit base for military cargo, but also one of the main drug dens on our territory," Mr Zyuganov told the crowd.
"We have to say a decisive 'No' to this betrayal of national interests."
The communist leader called for more protest marches on April 21, the eve of the birth of Vladimir Lenin, in all Russian cities - especially in Lenin's birthplace, Ulyanovsk.
Mr Zyuganov called on protesters not to "let the Nato boot step in the holy Russian land."
And 16 Ulyanovsk communists erected a tent camp outside the airport today kicking off an indefinite hunger strike against the the Western military alliance's plan.
Russian Foreign Minister Sergei Lavrov defended the proposed base last month, describing it as "a means to assist those who are eradicating the threats of terrorism and drug trafficking in Afghanistan."