One person was killed and 21 were injured when a bomb exploded in Nalchik, the capital of Russia's republic of Kabardino-Balkaria.
The bomb exploded during horse races as the city celebrated May Day.
A spokeswoman for the local Interior Ministry said the bomb was equipped with a timer and filled with pieces of metal designed to injure as many people as possible.
Law enforcement officials said the bomb exploded near a VIP box. A republic cabinet minister was among those wounded.
Kabardino-Balkaria is near the restive North Caucasus republics of Chechnya, Ingushetia, and Daghestan, but the level of violence there has been much lower so far than in the other three regions.
In Ingushetia today, a man was shot dead by policeman after opening fire at a sports complex.
The man opened fire after police began to search him at the entrance to the sports complex in the city of Nazran, where Ingushetia's president and other officials were attending a national judo competition.
compiled from agency reports