Russia Uses Iranian-Made Drones to Strike Military Base Deep Inside Ukraine

It was the closest drone attack to the capital since Russia began using the kamikaze-style munitions widely on the battlefield.

Smoke could be seen rising on Wednesday afternoon from the base housing Ukraine’s 72nd Brigade, which defended Kyiv against Russia’s assault in the early days of the invasion and is now fighting in the eastern city of Bakhmut. The roof of a building in the compound had caved in, its windows shattered from what appeared to be multiple strikes on the facility. Firefighters marched in and out of the compound.

Dozens of uniformed soldiers, including some who said they had recently returned from the fighting in eastern Ukraine, huddled in groups across the street from the complex. Their barracks now destroyed, they said they awaited orders for where they were heading next.

The drone attack began around 1:30 a.m. local time, according to several residents in the neighborhood around the base, with a buzzing sound that sounded like a motorcycle. Three residents said they didn’t understand the sound signaled an airstrike until they heard an explosion, which sent civilians and some soldiers from the barracks racing for their basement shelters.

The fact that drones were able to strike far inside the country is concerning for Ukrainian officials.

At a meeting with representatives of the country’s security and intelligence apparatus convened on Wednesday, Ukrainian President

Volodymyr Zelensky

discussed how to counter “new types of weapons that the aggressor has begun to use.” They also discussed stabilization in newly recaptured territories and preparing the army for winter, he said in a post online.

The Iranian drones had previously been used mainly in the northern Kharkiv region and on the southern coast near occupied Ukrainian territory. They are relatively small and fly at a very low altitude, making it hard for Ukrainian air-defense systems to detect them.

Air-force spokesman

Yuriy Ihnat

said the drones used in Wednesday’s attack had been launched from Russian-occupied territory in the south of the country. Six other drones were shot down, he said, adding that Russia was probing Ukrainian air defenses for weak points.

“The threats are serious,” Mr. Ihnat told a Ukrainian TV broadcast.

An aide to a minister in a Moscow-backed quasi-statelet in eastern Ukraine confirmed Russia had carried out a strike on the base in Bila Tserkva using Iranian kamikaze drones.

The strikes came as Ukraine pushed back Russian forces in areas that Moscow last week said it was annexing following sham referendums aimed at legitimizing the land grab. So far, only North Korea has recognized the votes.

In his nightly address, Mr. Zelensky said dozens of towns and villages had since been retaken in regions seized by Moscow, including Kherson. “The Ukrainian army is carrying out a pretty fast and powerful advance in the south of our country as part of the current defense operation,” Mr. Zelensky said.

Kremlin spokesman

Dmitry Peskov

said Wednesday that Moscow would retake territories it had lost since announcing their incorporation into Russia.

Russian President

Vladimir Putin

has threatened to use all means at Moscow’s disposal, including nuclear weapons, if Russian-claimed territory is attacked. Western officials played down the likelihood of Russia using nuclear weapons in retaliation for its losses on the battlefield.

After taking back the strategic town of Lyman over the weekend, Ukrainian forces are pushing further east toward the Luhansk region, most of which is occupied by Russia.

“Several settlements have already been liberated from the Russian army,”

Serhiy Haidai,

the Ukrainian governor-in-exile of the Luhansk region, said in a video on Wednesday, without specifying which ones. “The de-occupation of the Luhansk region has begun.”

The U.K.’s Ministry of Defense said Ukrainian forces were advancing toward the town of Svatove in Luhansk after consolidating substantial territory on the eastern bank of the Oskil River, which they crossed during a rapid offensive in the Kharkiv region. The gains could bring the road between Svatove and Kreminna within range of artillery fire, putting further strain on Russia’s ability to resupply its units in the east, it added.

“Politically, Russian leaders will highly likely be concerned that leading Ukrainian units are now approaching the borders of Luhansk [region], which Russia claimed to have formally annexed last Friday,” the defense ministry said.

Mr. Haidai said Russian forces were planting mines around Kreminna to slow an expected Ukrainian advance. Russia has also shut down mobile phone networks there to prevent residents who oppose Russia’s occupation from cooperating with Ukrainian forces, Mr. Haidai said.

As Ukrainian forces close in, civilians have been moved out of local hospitals to make space for wounded Russian soldiers, he added.

Russia’s Defense Ministry didn’t immediately respond to a request for comment on those allegations or on reports of further Ukrainian advances.

An offensive in the southern Kherson region has also gained momentum in recent days, with Ukraine’s armed forces saying they had recaptured eight villages.

Russian forces are seeking to slow Ukrainian advances there by destroying some bridges and crossings while bringing up reserves and falling back to safer positions, according to Ukraine’s southern operational command.

—James Marson and Olya Fokaf contributed to this article.

Write to Jared Malsin at jared.malsin@wsj.com and Isabel Coles at isabel.coles@wsj.com