About 1,000 opposition activists have protested Russia's plans to establish a military air base in Belarus, saying it would turn the former Soviet republic into a Kremlin "vassal."

They claim the base would add to regional tensions already heightened by the conflict in Ukraine, and make it impossible for Belarus to maintain neutrality between Russia and the West.

Belarus borders Russia, Ukraine and three members of the European Union and NATO: Lithuania, Latvia and Poland.

Belarusian President Alexander Lukashenko has refrained from commenting on Russian President Vladimir Putin's initiative to establish the base. Analysts say he has little choice but to accept it, since his government depends on cheap energy supplies from Russia.

Sunday's protest came one week before a presidential election expected to give Lukashenko a fifth term.