No fatalities were reported but RIA Novosti news agency said two people were in a grave condition. ITAR-TASS reported that leaders of the republic, including President Arsen Kanokov, did not attend the race meeting.
Kabardino-Balkaria is near Chechnya, Ingushetia and Dagestan but the level of attacks there has been much lower so far than in the other three regions.
One of the most populous regions in the mainly Muslim north Caucasus, Chechnya which declared independency after the collapse of the Soviet Union in 1991 but was attacked by Russian forces in two wars since the mid-1990s.
Still low-level insurgency continues in Muslim states controlled by Russia.
"(The blast) could be revenge by extremists for the destruction of the leaders of bandit groups and could be aimed at destabilising the situation in the republic during May holidays," ITAR-TASS quoted Kanokov as saying.
Reuters
