Moscow police have taken a top opposition member into custody for breaking the terms of his house arrest.
Police detained Alexei Navalny on Wednesday as he left a Moscow radio station. They plan to turn him over to federal authorities.
One day earlier, authorities fined Navalny $10 for cutting off his ankle bracelet, which electronically monitors his movements. They also blocked his website.
Navalny and his brother, Oleg, were convicted last month on charges of defrauding a French cosmetic company of $500,000.
Alexei was given a 3-1/2-year suspended prison sentence. Oleg was given the same term, but was ordered to prison.
Oleg is not politically active but Kremlin critics say he was jailed in an effort to silence his brother, who is a well-known opposition blogger and lawyer.
The European Union and United States have criticized the case against the Navalny brothers. They believe the fraud charges against them are politically motivated.