Russia is using suicide drones in Ukraine. They’re coming from an unlikely source.

In recent days, residents of the Ukrainian cities of Kyiv and Odesa say they have been hearing the buzzing sound of drones overhead more often.

Some have been capturing them in videos and photos, documenting how they are being used by Russian forces as deadly weapons and a means to sow fear in civilian areas.

In Odesa, for example, the Russians used to attack places on the outskirts of the city, said Volodymyr Dubovyk, who teaches international relations at Odesa National University.

“But with the drones attack, they [are] very visible and people [are] basically getting their heads up in the sky and seeing them buzzing,” he said. “And, it’s terrifying because it’s slow moving and no one knows where they’re going.”

Russia has intensified its attacks on civilian areas in recent weeks following major losses in several regions in Ukraine. These attacks also follow a truck bomb attack on the Kerch Bridge on Oct. 8, which was a strategic route linking annexed Crimea to Russia. Ukraine has not publicly claimed responsibility, and Russia announced this week it has arrested eight suspects, including five Russians and three citizens of Ukraine and Armenia.

Part of Russia’s response to losses in Ukraine and the bomb on the Kerch Bridge has involved the use of “kamikaze” or suicide drones.

Ukraine’s president, Volodymyr Zelenskiy, accuses Iran of providing these drones to Russia and has asked the international community for more air defense support.

Analysts say intelligence reports as well as video footage and photos from the ground support Zelenskiy’s claim. They say Shahed-136 delta-wing and ​the Mohajer-6 are being deployed in Ukraine. Some of these Iranian drones, they add, are repainted and rebranded in Russia.

Dubovyk, who is currently a visiting professor at Tufts University in Massachusetts, described the use of Iranian drones to attack Ukraine as “humiliating for the Russian military.”

That’s because “They always praised themselves as the strong military which has enough of these weapons but it turns out it doesn’t,” he said.

Last month, Ukraine responded to Russia’s use of Iranian drones on its territory by downgrading its diplomatic ties with Tehran.

Russian presidential spokesman Dmitry Peskov has called the accusations “bogus” and Iranian officials have denied sending drones to Russia.

Iran’s Foreign Minister Hossein Amir-Abdollahian said “the Islamic Republic of Iran has not and will not provide any weapon to be used in the war in Ukraine. We believe that the arming of each side of the crisis will prolong the war,” he said, according to a readout of his call with his Portuguese counterpart published on Saturday.

But Peter W. Singer, a strategist with the New America think tank and author of “Wired for War,” pointed to evidence that connects Iran to the drones.

“The first is trackers who have been tracking the movements of cargo planes from Iran during this period to Russia,” he told The World, adding that a variety of pictures of them in action has appeared online. US and British intelligence reports also support the claim they are being used.

“So, put me in the camp of no, I don’t believe Iran, in this instance, that they’re not playing a role,” Singer said.

The Shahed-136 drones are cheap and easy to make, he said. They carry explosives and self-destruct once they hit their target — that’s why they are called suicide or kamikaze drones.

In the air, they’re actually slow moving — “Snoopy and his biplane back in World War 1 could actually fly faster than them,” as Singer put it, but they are having an impact on the ground, partly because the Russian military deploys them in batches or swarms.

“It means they can be in a high number. They can also be in multiple different places,” he said.

The news that Russia is relying on Iranian drones says a lot about the state of its military capabilities, Samuel Bendett, an expert on Russia’s military and weapons at The Center for Naval Analyses, a nonprofit research and analysis organization in Arlington, Virginia, told The World.

“How is it that one of the most-advanced militaries in the world is unable to manufacture relatively cheap, loading munitions at scale?”

Bendett said that Russia quickly ran through a large number of its domestic drones in the first few months of the war and faced a gap in its capabilities, which its own domestic industry was unable to address fast enough.

“They need something right now and not a month from now or two months from now,” he said.

That’s where Iran comes in.

Iran has been developing its own unmanned aerial vehicles for decades, Bendett explained. It has been supplying them to militias in Iraq, Syria, Yemen and Lebanon.

“So, all of that accumulative experience over many decades is basically resulting in a current Iranian drone lineup. Russia really doesn’t have that long-term expertise. Even though it was one of the major military powers during the Cold War that also used UAVs. A lot of that expertise was lost in the 1990s and early 2000s,” he said.

Ukraine is also getting drones from the US and Turkey. And in response to Zelenskiy’s repeated pleas for more effective air defenses, the British government announced it would provide missiles for advanced NASAM anti-aircraft systems that the Pentagon plans to send to Ukraine, according to the Associated Press.

The UK is also sending hundreds of aerial drones for information-gathering and logistics support, plus 18 howitzer artillery guns.

“These weapons will help Ukraine defend its skies from attacks and strengthen their overall missile defense alongside the US NASAMS,” UK Defense Secretary Ben Wallace said.

Singer said that these weapons are unlikely to determine which side is going to win the war. But their impact cannot be ignored.

In the past, he said, there was a debate within military circles about the value of drones in conventional warfare.

“The events of the last months have ended that debate. It does give us a taste of hey, we’re going to see a lot more of this,’ not just in the war in Ukraine but in all wars to come,” Singer said.