At least 15 people were injured in an explosion on Tuesday in the center of the southern Russian city of Pyatigorsk, a doctor working at the scene said.
It was not clear if anyone was killed in the attack, he said.
A local police source confirmed that people were also injured in the blast, but did not specify how many.
A police officer said the blast came from an explosion in a car, parked near a cafe.
Windows are broken in buildings 200 meters from the site of the explosion.
Pyatigorsk is the capital of Russia's North Caucasus Federal District, which includes the volatile Russian republics of Chechnya, Dagestan and Ingushetia.
PYATIGORSK, August (RIA Novosti)