Six people were injured in Friday's blast in Grozny, the capital of the volatile Russian North Caucasus republic of Chechnya, a spokesman for the regional Investigative Committee department said on Friday.
"An investigation is underway. According to updated information, six people were injured," the spokesman said, RIA Novosti reported.
The explosive device was planted under paving slabs on Dagestanskaya Street near the Berkat shopping mall in downtown Grozny.
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.