Fourteen people, including a four-year-old boy, were injured on Saturday in almost simultaneous bomb explosions in two supermarkets in the Ukrainian town of Kharkiv, local officials said.
Eight of the injured were taken to hospital but their lives were not in danger, an official at the town hospital informed.
Police and officials from the emergencies ministry said, "incendiary devices" had been placed in two supermarkets, located 200 metres apart in a residential area of the town.
They took place just before midday, just eight minutes apart, police said.
Two teams of investigators had been sent to the scene.
The shops' windows were shattered and the interiors badly damaged in the blasts.
The owners of the supermarkets had received messages demanding money and threatening to bomb attacks if they refused, sources close to the authorities said on condition of anonymity.
A month ago there was a smaller explosion at one of the supermarkets but there were no casualties.