Moscow police have arrested dozens of people protesting against military intervention in Ukraine.
The Interfax news agency quoted police as saying 40 people were detained for "attempts to violate public order" at a protest near the Defense Ministry in central Moscow.
Ovdinfo, a rights group that tracks arrests at demonstrations, put the number of detentions at 100.
Antiwar protesters also gathered at a separate demonstration on Manezhnaya square close to the Kremlin and Red Square, which police cordoned off and blocked with parked buses.
People held posters saying "No to war," while some also held Ukrainian flags and ribbons in the national colours of yellow and light blue.
Ovdinfo said about 30 people were detained.
Meanwhile, a march by Russians in support of Kremlin policy in Ukraine took place in central Moscow without any incidents.
The Moscow city police department said the pro-Kremlin rally drew about 27,000 participants.
This report provided by RFE/RL was based on reporting from the Interfax and AFP news agencies.