Two blasts were heard in the Russian city of Belgorod near the border with Ukraine on Sunday, two witnesses told Reuters, days after Russian authorities accused Ukrainian forces of striking a fuel depot there.
The cause of the blasts was not immediately clear. One witness said the blasts were so powerful that they rattled the windows of her home in Belgorod.
The blasts come days after Russia's defence ministry said two Ukrainian helicopters struck a fuel depot in the city, some 35 km (22 miles) from the border with Ukraine, after entering Russia at extremely low altitude in the early hours of Friday.
