Ukraine’s drones range from small, autonomous boats patrolling the Black Sea to aircraft that travel hundreds of kilometres into Russia. Most are designed to be made from parts that are cheap, easy to find and simple to put together,

Apart from drones, 20 missiles of various types were fired at different parts of Ukraine, according to the air force, which said the barrage targeted mainly central and western areas of Ukraine.

The Ukrainian military says its new weapon system, which launches antiaircraft missiles from a remote-controlled speedboat, has brought down two Russian jet fighters.

Ukraine recently used inexpensive drones to inflict serious damage to Russia's strategic bomber fleet in an audacious attack.