As Russians voted in local and regional elections on Sunday, democracy advocates in the only region where they were allowed to run accused the authorities of fraud and said the police had blockaded an apartment where opposition activists were tracking the vote. Although candidates from President Vladimir V. Putin’s United Russia Party were widely expected to win, Sunday’s vote was being viewed as a dress rehearsal for 2016 parliamentary elections and a test of voter turnout amid an economic downturn and Western sanctions. Results were expected on Monday. In the Kostroma region, about 200 miles northeast of Moscow, a coalition of opposition politicians, including Aleksei A. Navalny, fielded candidates under the banner of Parnas, or People’s Freedom Party. Boris Y. Nemtsov, a political reformer who was shot dead near the Kremlin in February, was the party’s co-founder. Kostroma’s electoral commission granted Parnas approval to run only last month, after several attempts to keep its candidates from running for the regional legislature.
Mr. Navalny, who is barred from running for office because he is serving a suspended prison sentence on a fraud conviction, has campaigned for the coalition’s candidates and was in Kostroma on Sunday night. He posted on Twitter that, according to the coalition’s own exit polls, United Russia had won 47 percent of the vote, while Parnas had 6 percent, crossing the 5 percent barrier required to qualify for seats in the legislature.
But Vtsiom, a state-owned polling agency, said its exit polls showed Parnas with just 2.6 percent of the vote, and opposition activists posted on Twitter that they were preparing for a long night ahead.
Opposition activists said the police had raided an apartment housing the local headquarters of Open Elections, a monitoring arm of Open Russia, the civil society foundation of Mikhail B. Khodorkovsky, the former oil tycoon and Putin opponent who spent a decade in jail. Activists recorded a police officer on camera as saying that officers were responding to a call that someone had been killed in the apartment.