MINSK, Belarus (AP) — About 1,000 opposition activists on Sunday 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.

Police did not interfere in the protest, which was organized by leading opposition figures, including Nikolai Statkevich, a former presidential candidate who was released in August after five years in prison.

Another opposition leader described the Russian base as a point of no return for Lukashenko. "After this, Belarus will become a full vassal of the Kremlin and Lukashenko will not be able to stay neutral," said Alexei Yanukevich.

Russia already has radar and a navy communications facility in Belarus, but this would be the first base.

Sunday's protest came one week before a presidential election expected to give Lukashenko a fifth term. His challengers are the leaders of two pro-government parties and a little-known opposition activist.

"No one doubts Lukashenko's victory," said opposition leader Yuras Gubarevich. "And it is already clear what the Kremlin demanded in return for its support of Lukashenko by supplying cheap oil and gas."