At least seven people were killed in southern Russia on Monday after debris from a Ukrainian drone fell onto a crowded beach, according to local officials, in one of the deadliest incidents in recent weeks.

Three of those killed in the incident in a Black Sea resort area in the city of Gelendzhik, were children, local authorities in the Krasnodar region said in a statement.

It is unclear whether the incident was caused by the drone being shot down by Russian air defenses or the drone crashing.

Regional governor Veniamin Kondratiev said the people on the beach were killed “when debris from a UAV fell.”

A further 40 more people were injured in the incident, Kondratiev said. Of those, 21 were hospitalized and 19 others received medical treatment, local authorities said.

Kondratiev expressed his “sincere condolences to their families and loved ones.”

CNN’s analysis of video that shows the drone hitting the beach found that seconds before the explosion, automatic gunfire from at least three weapons is audible. During the gunfire, the drone veers sharply and dives into the beach. The drone appeared to overshoot a Russian radar installation just west of the beach where it came down.

In a statement to CNN, the head of the Ukrainian government’s Center for Countering Disinformation, Andriy Kovalenko, said: “This was the work of Russian air defense forces, which shot down the drone over a beach full of vacationers. And pathetic efforts by the Russian authorities, who often conceal air raid alerts or fail to do everything necessary to ensure Russians’ safety during such alerts.”

“The deaths of Russians on the beach in Gelendzhik are entirely the fault of the Russian air defense forces,” Kovalenko said. “Ukraine uses its weapons exclusively against Russia’s military-industrial complex (and) economic infrastructure that affects Russia’s ability to finance the war.”

Russia’s Krasnodar region is frequently targeted by Ukrainian forces, where they have previously attacked naval assets and oil infrastructure.

The Novorossiysk Naval Base, which is the primary hub for Russia’s Black Sea Fleet, is located about 25 miles away from the resort town of Gelendzhik. Russian President Vladimir Putin also reportedly has a palace near the town, though the Kremlin’s spokesperson has previously denied the Russian leader was linked to any estate there.

Over the past month, Ukraine has edged up lethal strikes on Russia, targeting energy infrastructure, factories making weapons, military hardware sites and shipping facilities. At least 61 people were killed and 327 others wounded from July 24 to July 31 by Ukrainian drone strikes and shelling, Russian Foreign Ministry spokesperson, Maria Zakharova, said on Friday. On July 18, at least eight people were killed by Ukrainian drone attacks in Russia – marking the deadliest salvo reported inside the country in more than two years.

That same month in Ukraine, Russian attacks killed at least 377 civilians and injured 2,129 others, making it the deadliest month of the invasion since April 2022.

CNN’s Avery Schmitz, Tim Lister and Svitlana Vlasova contributed reporting.

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Russia says seven killed as Ukrainian drone hits crowded Russian beach