Amnesty International has accused Russia of mounting a "fierce crackdown" on political activists ahead of this week's presidential election, systematically violating their rights through "arbitrary" arrests and detentions.

The London-based rights group said on March 15 that Russian authorities are using a draconian law on public assemblies to "deliberately" target activists calling for an election boycott. In addition, many prominent opposition voices have been arbitrarily detained and charged with politically motivated offenses.

"The Kremlin’s agenda is crystal clear -- the loudest protesters and vote-boycotters must be cleared from the cities' streets during the final stages of the presidential campaign," Denis Krivosheev, deputy director for Eastern Europe and Central Asia at Amnesty International, said in a statement.

"While various methods are used, the authorities usually turn to their favorite one: arbitrarily throwing dissenters behind bars."

Eight candidates are on the ballot in the March 18 presidential vote, but incumbent Vladimir Putin -- who has been president or prime minister of Russia since 1999 -- appears certain to win another six-year term as president.

Opposition politician Aleksei Navalny, who was barred from the ballot because of a criminal conviction he and his supporters say was engineered by the Kremlin, has been urging Russians to boycott an election he has denounced as undemocratic and a "reappointment" of Putin.

'Crude' Intimidation Tactics

Navalny’s campaign chief, Leonid Volkov, was detained in a Moscow airport on his way to the city of Ufa on February 22.

The same day he was sentenced to 30 days of administrative detention for allegedly organizing an "unauthorized gathering," a reference to January 28 "voters' strike" rallies held in more than 100 cities across the country in support of an election boycott.

That came after Denis Mikhailov, the coordinator of Navalny's headquarters in St. Petersburg, was detained on January 31 for 30 days after the "voters' strike" event in that city.

He was initially held for calling for "an unauthorized gathering," but was released on March 2 before being rearrested the same day, this time for "participating" in the Saint Petersburg event. He was sentenced to another 25 days in prison.

"Denis Mikhailov was not only arbitrarily deprived of his liberty, but deprived twice over. This repeated violation epitomizes the increasingly hostile situation peaceful protesters are facing ahead of the election," Krivosheev said.

At least two more prominent activists -- Andrei Pivovarov, the local leader of the Open Russia NGO, and Artyom Goncharenko, a member of another opposition movement, Vesna (Spring) -- suffered similar attacks on their freedom, Amnesty said.

"This election campaign has been marred by widespread attacks against President Putin’s critics, and reprisals aimed at intimidating opposition activists into silence are becoming cruder as polling day approaches," Krivosheev said.

"All protesters and political activists arrested solely for peacefully exercising their rights to freedom of assembly and expression must be immediately and unconditionally released," he said.

