Ukraine has accused Russia of using "kamikaze" drones against civilian targets in Kyiv. These carry explosives which detonate on impact, destroying the drone in the process. What is Russia's 'kamikaze' drone? It's believed Russia has been using the Iranian-made Shahed-136 drone in the Ukraine conflict since mid-September. Also called the Geranium-2 by Russia, it has explosives in a warhead on its nose and is designed to loiter over a target until it is instructed to attack. The Shahed-136 has a wingspan of about 2.5m (8.2ft) and can be hard to detect on radar. It's unclear exactly how many Russia has, but the US has said Iran planned to send hundreds to Russia. Iran has denied doing so. How have military drones been used? For both sides - Russia and Ukraine - drones have been effective for locating enemy targets and guiding artillery fire toward them. "Russian forces can bring their guns to bear on the enemy within only three to five minutes of an Orlan-10 drone spotting a target," says Dr Watling. An attack could otherwise take 20-30 minutes to carry out. Dr Marina Miron says drones have allowed Ukraine to stretch its limited forces. "If you wanted to seek out enemy positions in the past, you would have had to send out special forces units... and you might lose some troops," she says. "Now, all you're risking is a drone." In the first few weeks of the war, Ukraine's Bayraktar drones were widely praised. "They were shown attacking targets such as ammunition dumps, and played a part in the sinking of the Moskva [warship]," Dr Miron says. However, the Bayraktar is a large and slow moving drone, and Russia has been able to counter it effectively with its air defence systems. How are the non-military drones being used? Military drones are expensive to replace - a single Bayraktar TB2 costs about $2m (£1.7m). So, both sides - but especially Ukraine - also use small, commercial models, such as the DJI Mavic 3, which costs about £1,700. These commercial drones can be fitted with small bombs. However, they are mainly used to spot enemy troops and to direct attacks. "Ukraine doesn't have as much ammunition as Russia," says Dr Miron. "Having 'eyes in the sky' to spot targets and direct artillery fire means they can make better use of what they have." But commercial drones are much less capable than military ones. For example, the DJI Mavic's total flying distance is only 30km, and it can only fly for a maximum of 46 minutes. Russia is using electronic devices to counter them, says Dr Miron. "Russian forces have the Stupor rifle, which shoots electromagnetic pulses," she says. This stops commercial drones from being able to navigate using GPS, she explains. Russian forces have also used online systems, such as Aeroscope, to detect and interrupt communications between commercial drones and their operators. These systems can cause a drone to crash or return to base, and can stop it sending back information.