Visitors to a Moscow cafe escaped injury in the early hours of Friday when a small improvised explosive device detonated, a police source told RIA Novosti.
The blast – equivalent to 200 grams of TNT – hit the summer terrace of a café in the north-west of the Russian capital, he said. The cafe was slightly damaged.
Police are carrying out an investigation. No group has claimed responsibility.
Violence is often used to settle business disputes in Russia, while both Islamist terrorists and nationalist groups have used explosives in past attacks.
MOSCOW, May 13 (RIA Novosti)