At least 22 people were injured in an explosion in the centre of the southern Russian city of Pyatigorsk, a spokeswoman for the local emergencies department said.
"All the injured have been hospitalized in Pyatigorsk hospital," she said.
A doctor working at the scene said earlier that 16 people were injured.
A car, parked near a cafe, exploded at 16:30 Moscow time (12:30 GMT). Police are still uncertain whether the blast was caused by a bomb in the car or an exploding gas cylinder.
President Dmitry Medvedev ordered the head of the Russian Federal Security Service (FSB) to do everything possible to get to the bottom of the incident.
Pyatigorsk is the capital of Russia's North Caucasus Federal District, which includes the volatile republics of Chechnya, Dagestan and Ingushetia, where terrorist attacks and militant clashes are common.
PYATIGORSK, August 17 (RIA Novosti)
