Police have searched a Moscow office of Open Russia, an NGO backed by Kremlin foe Mikhail Khodorkovsky, stepping up pressure on the group two days before street protests it's seeking to organize.
Activist Maria Baronova said that 15 riot police came to the office at 4 p.m. on April 27 (1200 GMT/UTC) along with several other police. She said they presented no court order and gave no explanation for the search.
Open Russia Chairman Aleksandr Solovyov also reported the search on Twitter, saying the police had barred staff members from using their telephones.
"Authoritarianism in frontal view and in profile," Khodorkovsky said in a tweet with a photo showing camouflage-clad officers in an office hallway.
The search came a day after the Prosecutor-General's Office declared Open Russia to be an "undesirable" organization under a 2015 law the government has used to ban foreign organizations it claims pose a threat to the country.
A spokesman for the prosecutor's office said the designation applied only to Open Russia entities registered abroad, but the search increased pressure on the organization.
Open Russia has called for protests against President Vladimir Putin's government on April 29, seeking to build on anticorruption demonstrations that brought tens of thousands of people into the streets on March 26.
Putin's spokesman, Dmitry Peskov, told reporters on April 26 that the authorities would react "within the framework of the law" if the unsanctioned rallies went ahead.
The March 26 protests were organized by opposition politician Aleksei Navalny, who is trying to get on the ballot in March 2018 election in which Putin is expected to seek and win a new six-year term.
Khodorkovsky, once Russia's wealthiest businessman, built up Russia's largest oil company before he was imprisoned on charges his supporters say were trumped up, and the company's assets were stripped away by the state.
Khordorkovsky became an exile following his release in 2013 after 10 years in prison and lives in Britain, where he has gradually been building up Open Russia's profile and positioning it as a leading opposition force in Russia.
He has called on supporters to back Navalny's presidential bid.