Russia's FSB security service said Sunday it had seen a "considerable increase" of Ukrainian fire into its territory in recent days, claiming one person had been killed and five wounded in the past week.

"Since the start of October, the number of attacks from Ukrainian armed formations on Russia's border territory has considerably increased," said the FSB which is responsible for border security.

The attacks have concentrated on the Russian region of Belgorod, near the Ukrainian city of Kharkiv, as well as Bryansk and Kursk, the FSB said.

It said that in the past week "more than 100 bombardments were recorded in 32 localities, with the use of multiple rocket launchers, artillery, mortars and drones".

A child was among those wounded, the FSB said, adding that the attacks also "destroyed two electricity stations, 11 residential buildings and two administrative buildings."