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.

The overnight attack was one of the largest on Ukraine and included strikes in the western part of the country, which is hit less often.

Ukrainian drones struck the Russian city of Izhevsk, over 800 miles from the two countries’ border. The attack killed three people and injured dozens, according to local officials. Ukrainian sources report that the target was the Kupol plant,