President Volodymyr Zelenskiy said Ukrainian forces struck several military and energy infrastructure sites, including a military factory that he said supplied components for Russian drones and missiles.
In a post on social media on Wednesday, Zelenskiy said Ukrainian FP-5 Flamingo long-range missiles had hit the facility in Cheboksary, in the Chuvashiya region more than 900km from the front line.
Russia's defence ministry said that air defences downed 326 Ukrainian drones overnight.
Oleg Nikolayev, the head of Chuvashiya, confirmed that the missile attack but did not give details.
The Astra online news outlet reported that the Ukrainian strike hit the VNIIR-Progress plant that produces antennas for drones.
Zelenskiy also said Ukrainian forces struck a refinery in Russia's Samara region, where governor Vyacheslav Fedorishchev said several industrial plants were damaged by drone strikes and three people were injured.
Fedorishchev did not name the facilities that were damaged, but Astra carried images of a large fire at the Samara refinery.
Zelenskiy said Ukraine's Security Service had also targeted two oil infrastructure facilities in Russia's Vladimir region, about 700km from the front line.
In Russia-occupied Crimea, a Ukrainian drone hit the building housing a huge panorama painting depicting the defence of the city during 19th-century Crimean War.
Mikhail Razvozhayev, the Kremlin-appointed head of Sevastopol, said the painting by artist Franz Rubo was effectively destroyed.
As the more than 1000km front line in the four-year war has remained largely static as swarms of drones hinder advances, both sides have increasingly relied on long-range strikes.
The increasingly deep and audacious Ukrainian strikes have cast a challenge to Russia's President Vladimir Putin, defying his claim that Moscow was winning the war now in its fifth year.
Putin vowed to strengthen Russia's air defences after Ukrainian attacks set ablaze an oil terminal in St Petersburg and also hit a nearby naval base on June 3, casting a cloud on his showcase economic forum in his home town.
The attacks on St Petersburg came as another embarrassment for the Russian leader, weeks after he pruned back an annual Victory Day parade in Moscow because of fears of Ukrainian drone attacks.
Ukraine's air force says air defences downed 181 of 207 Russian drones.
A barrage of 26 drones struck Kharkiv early on Wednesday, injuring at least four people, according to regional administration head Oleh Syniehubov.
He said one person was killed and 15 others were injured in the region in the past 24 hours.
In Zaporizhzhia and its region, 10 people were injured overnight in a series of Russian aerial attacks, according to regional head Ivan Fedorov.
In Odesa, a mother and two children, aged 8 and 10, required medical attention after Russian drones damaged two residential buildings, according to regional administration head Oleh Kiper.
