Both sides in the more than three-year war following Russia’s February 2022 invasion of its neighbor have raced to improve drone technology and enhance their use on the battlefield.

Three people have been killed and 35 taken to hospital following an attack by Ukraine on a factory in the city of Izhevsk - more than 1,000km (620 miles) from the border, Russian authorities say.

A Ukrainian drone attack at an industrial plant in central Russia has killed three people and injured 35 others, a Russian regional governor has said.