They're slow, loud and 'bargain-basement.' So why is Russia using kamikaze drones against Ukraine?
Kyiv was hit by a flurry of drone attacks on Monday, killing at least 4
Ukraine's capital city of Kyiv was struck on Monday by a flurry of suicide drones that attacked residential areas, causing widespread damage to buildings, setting them afire while killing at least four people.
These weapons, also known as kamikaze drones, are not new to the battlefield, having been used to attack military and infrastructure targets in southern Ukraine since September, the Washington Post reported.
But their use on civilian targets raises questions of whether this is a new strategy by Moscow or a sign of a problem with its military campaign.
CBC explains what these drones are, their advantages and disadvantages, and why Russia is using them against Ukraine.
What are kamikaze drones?
They're known as "loitering munitions," but also have been labelled suicide or kamikaze drones. They are used once, destroying themselves when they hit their target, much like the Japanese pilots in the Second World War who flew suicide missions into U.S. warships and aircraft.
"They are strapped with explosives, payloads, various things like that," said Nicholas Carl, the Middle East portfolio manager of the American Enterprise Institute's Critical Threats Project. "So the Russians can target them at various locations."
But unlike missiles that go straight from launch to their target, drones can hover — waiting hours before they strike.
U.S. and Ukrainian officials say these specific drones are Shahed 136s, manufactured by Iran. Ukrainian President Volodymyr Zelenskyy has said that, according to their intelligence, Russia has ordered 2,400 Shaheds from Iran, though Iran denies having supplied any such drones to Russia.
They are relatively small; about 3.5 metres long and two metres wide, weighing around 200 kilograms and powered by a 50-horsepower engine with a top speed of 185 km/h, according to the Ukrainian online publication Defence Express. They can be launched from the back of a truck.
What are their disadvantages?
These particular drones are like "crude and bargain-basement" cruise missiles, wrote Douglas Barrie, a senior fellow for military aerospace with the International Institute for Strategic Studies.
They're not very accurate and are slower, for example, than an actual cruise missile. So they can be shot down more easily and are vulnerable to jamming, said Christopher Tuck, an expert in conflict and security at King's College London.
"They are pretty low-end, they're slow and they're pretty noisy," Tuck said. "They really aren't very sophisticated."
The loud buzzing made by the motor has earned them another nickname: "moped" missiles.
The Shahed 136s also don't carry much explosives — the payload for one is about equal to three mortar shells, Carl said, meaning they have "limited utility" against Ukrainian forces.
So why are Russians using them?
The Russians are primarily firing Shahed 136s at civilian targets and critical infrastructure, Carl said, perhaps to "sow panic and discord," as some Ukrainian officials have suggested.
They are also very cheap, Barrie wrote.
At $20,000 apiece, the Shahed costs only a tiny fraction of a more conventional, full-size missile. For example, Russia's Kalibr cruise missiles, which have seen widespread use in the eight months of the Ukraine war, cost Moscow about $1 million each.
And, as Barrie points out, the low cost allows a military to use them in numbers — or swarms — against area targets.
Ukraine is able to shoot down most of them, and it's just those few that actually make it through that have caused the most visible damage, said Samuel Bendett, an adviser at the Center for Naval Analyses think-tank.
"The whole point of launching these … is to essentially try to overwhelm the [Ukrainian] air defences, and keep them busy, to try and shoot down every single one of them. And only one really needs to get past," Bendett said.
These drone strikes are also intended to show that the entire country of Ukraine is in play, Bendett said, that any place is a potential target.
"It need not be just a military strike. It could be a strike on the civilian infrastructure. So it's not just a military weapon, it's also a psychological weapon. It signals to the Ukrainians that their skies are not exactly under control by their own government."
Still, a report by the Institute for the Study of War suggested that Russia's use of these drones is "unlikely to affect the course of the war significantly."
"They have used many drones against civilian targets in rear areas" — major cities away from the front lines — likely hoping to generate terror, the report stated. "Such efforts are not succeeding."
Does this suggest a problem with Russia's military campaign?
That same report cited Ukrainian air force spokesperson Yuri Ignat, who alleged that the Russian army is increasingly using the Iranian-made drones to conserve its stock of high-precision missiles.
That, said Tuck, "would indicate problems with the Russian campaign."
That's because aerial munitions — whether drones or missiles — are best used against key battlefield targets like artillery sites, headquarters, logistics hubs, or to help reduce enemy defensive positions which are particularly troublesome, he said.
What the Russians are doing with them would be better done with cruise missiles, Tuck said. He thinks the Russians are running low on missiles so "they're using what they do have, which are these loitering munitions."
"The attacks that are being launched, obviously, are very damaging," Tuck said. "But using these systems in the manner that they're being used, I think is more indication of Russian weakness than it is of strength."
With files from The Associated Press, Reuters