Two people, including an 8-year-old child, were killed in southern Russia by Ukrainian drone strikes, the regional governor said Wednesday, as cross-border attacks continue between the two countries.

Russian overnight strikes on a frontline city in southern Ukraine also killed two.

Ukraine has increased its strikes on Russia in what it says is fair retribution for Moscow's own daily strikes on Ukrainian cities that force people into shelters and kill civilians across the country.

Russia's Krasnodar – a southern region home to several tourist hotspots – saw a barrage of "several hundred" Ukrainian drones, regional Gov. Venyamin Kondratyev said.

"An 8-year-old child died in Novorossiysk ... Eight people, including one child, were also wounded and have been hospitalized," Kondratyev said on Telegram.

He added that debris from drones damaged 21 buildings in the port city, with unverified images on social media showing blocks of flats with blown-out windows and charred cars.

Ukrainian President Volodymyr Zelenskyy said that Kyiv had "carried out a unique operation targeting the naval base in Novorossiysk – the last major stronghold of the Russian fleet in the Black Sea, more than 300 kilometers from the front line."

"Hits on air defense positions, piers, and seaport infrastructure have been confirmed," he said on social media.

He posted a video from Russian social media showing the attack unfolding – streaks of orange air-defense flashes and blue counter-drone laser beams shining into the sky – and a thick grey cloud billowing over the city after dawn.

Another person was killed in the Krasnodar region when drone debris fell into the garden of a private house in the village of Volna.

Two people were also wounded in the resort town of Gelendzhik on the Black Sea coast.

Russia shot down 502 Ukrainian drones across its territory and the Black Sea overnight, its Defense Ministry said in a statement.

Ukraine's air force, meanwhile, reported Moscow attacked with missiles and 138 drones, 112 of which were shot down or intercepted, launched mostly at its southern Odesa region and Sumy in the northeast.

Russian drones killed two people in the frontline city of Kherson in southern Ukraine, the city chief said, including a woman whose house was hit.

Civilians are frequently killed in the city, with Russian troops based on the opposite side of the Dnipro river, which snakes through southern Ukraine.