Hours later, however, the police bowed to a mob of several hundred pro-Russian demonstrators who attacked their headquarters, smashing doors, windows and security surveillance cameras. Shortly after some of them managed to break into an inner courtyard, police released the detainees, who were swept up by the cheering, rain-dampened crowd that had been chanting "Freedom!"
The Interior Ministry said 67 activists had been released on prosecutors' orders. Prosecutors, however, later said they had nothing to do with the release and accused the police of failing to carry out their duties. It was not immediately clear whether any activists were still being held.
Putin spoke by telephone Sunday night with German Chancellor Angela Merkel, the latest in a series of discussions they have had about Ukraine. The Kremlin said they agreed on the importance of the role to be played by the Organization for Security and Cooperation in Europe, and said Swiss President Didier Burkhalter, whose country currently chairs the OSCE, would visit Moscow on Wednesday.
The interim government in Kiev, which took power in February, has renewed its push in recent days to quell the pro-Russian insurgency in the east, where government buildings have been seized in more than a dozen cities and towns.
Interior Minister Arsen Avakov said on his Facebook page that an "anti-terrorist operation" was being executed in the eastern city of Kramatorsk, the latest flashpoint for unrest.
A standoff Saturday in Kramatorsk culminated with pro-Russian insurgents setting buses ablaze to ward off attacks. Russian state TV reported 10 deaths, including two among government forces, during clashes there so far. The figures could not be independently confirmed.
By midday Sunday, however, there was little sign of movement, from either government or the insurgents. The burned-out trolleybuses and a minibus lay in the road untouched.