One man was injured in an explosion in Grozny, the capital of the volatile Russian North Caucasus republic of Chechnya, a law enforcement officer said Friday.

The explosive device was planted on the roadside near the Berkat trade center, he said.

Investigators are working at the site of the blast.

However, a spokesman for the regional Investigative Committee department told RIA Novosti that two passersby were injured - a man and a woman.

"An unidentified explosive device went off on Dagestanskaya Street in Grozny. According to preliminary data, two people were injured," he said, adding that the device was planted under paving slabs.

Russia fought two wars against separatists in Chechnya in the 1990s and early 2000s. Sporadic terrorist attacks, shootings and militant clashes are still common in Chechnya and the neighboring republics of Dagestan and Ingushetia.

GROZNY, July 30 (RIA Novosti)