The Russian Defense Ministry accused the Ukrainian military of attacking its positions in Russia's Kursk region on August 6, while Ukraine said its forces shot down drones, a missile, and a helicopter over the Sumy region on the other side of the border.
The Russian ministry said up to 300 fighters from Ukraine's 22nd Mechanized Brigade supported by 11 tanks and more than 20 armored fighting vehicles attacked the positions of Russian units near the settlements of Nikolayevo-Darino and Oleshnya in the Kursk region, which borders on the Sumy region of northeastern Ukraine.
Russian media quoted the Federal Security Service (FSB) as saying that Russian forces had dealt with an armed "provocation" by Ukraine.
Moscow said its forces repulsed the attacks using artillery fire, warplanes, and drones, and the Ukrainian forces retreated after suffering losses. The claims could not be independently verified.
The Russian Defense Ministry also claimed its forces defeated "reserves in the territory of the Sumy region."
The ministry said that Russian aircraft struck the "concentration of manpower and equipment of the armed forces" in and around several settlements in Sumy. There was no independent confirmation of the attacks.
The Ukrainian military's 22nd Mechanized Brigade did not comment on the claims but said border settlements of the Sumy and Chernihiv regions continued to suffer from Russian shelling.
The General Staff of Ukraine's military said that its forces shot down a Russian helicopter, a ballistic missile, and two drones over the Sumy region.
Earlier on August 6, at least one person was killed and several others were wounded in drone strikes reported by Russia and Ukraine, after Kyiv was targeted again in an overnight attack that caused damage to civilian infrastructure.
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Vyacheslav Gladkov, the governor of Russia's Belgorod region which borders Ukraine, said that one person was killed when a drone struck a vehicle, while in Kursk, another region that has a border with Ukraine, several people were wounded by falling debris from drones shot down by Russian air defenses.
Gladkov, who also issued a missile alert for the city of Belgorod and its surroundings early on August 6, said the strike that killed the civilian occurred near the village of Novostroevka, in Belgorod's Graivoronsky urban district.
His claim could not be independently confirmed.
In the Kursk region, 26 drones were shot down on August 6, acting regional Governor Aleksei Smirnov said, adding that five people were wounded by falling debris in Sudzha, a town some 10 kilometers from the Ukrainian border.
Smirnov also claimed that Russian border guards repelled an alleged attempt by Ukrainian forces to cross the border into the Kursk region. Ukraine has not commented on this matter and Smirnov's claim could not be independently confirmed.
Ukraine, whose civilian and energy infrastructure has been relentlessly pounded by Russian drone and missile strikes, has in recent months increasingly resorted to striking targets deeper inside Russian territory, mostly hitting oil refining facilities working for the military and energy infrastructure.
In Ukraine's south-central Zaporizhzhya region, two civilians were killed as a result of Russian shelling, Governor Ivan Fedorov said on August 6. Fedorov reported the deaths on Telegram, saying an aerial bomb was used in the attack, which also destroyed a house.
Ukrainian President Volodymyr Zelenskiy said that an earlier strike on the city of Kharkiv killed one person and injured 12. Authorities in the city said a Russian missile strike hit the city center, damaging residential buildings, a clinic, and 25 cars belonging to civilians.
In Ukraine, air defenses shot down 15 drones and four out of six missiles over the Kyiv, Kherson, Mykolayiv, and Khmelnytskiy regions early on August 6, the air force said in a message on Telegram, adding that two of the missiles were Iskander ballistic missiles and two were Kh-59 cruise missiles.
In the Kyiv region, falling drone debris caused damage to civilian infrastructure, including residential high-rise buildings, gas stations, and commercial structures, the region's governor, Ruslan Kravchenko, reported on Facebook. He added that no casualties had been reported.