Russians go to the ballot box for parliamentary elections from September 18 to 20 and there are signals the Kremlin could be nervous because earlier this week Russia's highest court barred an anti-war opposition party from participating.
Ivan Noskov, head of the region's capital, Samara, said air defence forces had repelled a "massive" missile attack, with "localised damage" to the city's industrial sites.
He also said that medical assistance has been provided to those injured in the attack, but did not give further details.
Ukraine has stepped up its long-range aerial attacks on Russian military industries and energy facilities, as the conflict hits its fifth year.
Writing on social media, Ukrainian President Volodymyr Zelenskiy said that Kyiv's forces had carried out a strike against Samara's Progress Centre, which operates under Russian space agency Roscosmos and is involved in producing rocket technology and electronics.
He said that the strike used Ukraine's domestically produced Flamingo missiles to hit the site, which is approximately 900km from the Ukrainian border.
Zelenskiy also said Russia's Savasleyka air base, some 700km from the front line, had also been hit.
"Peace is needed, and this must be evident in Russia — through concrete damage to specific facilities," Zelenskiy wrote.
While most of Ukraine's strikes have a range of less than 200km, its longer-range attacks have increased dramatically this year.
It launched three times as many of those strikes in July as it did in January, according to data from ACLED, an independent conflict monitor.
Repeatedly hitting deep into Russia has forced its military to stretch air defences over a larger area.
Russia's Ministry of Defence said on Saturday that it had shot down 598 Ukrainian drones over 19 Russian regions, as well as the Black and Azov Seas and the annexed Ukrainian peninsula of Crimea.
Separately, two people, including a nine-year-old child, were wounded when a Ukrainian drone attack hit a private home in the town of Shatura in the Moscow region, local Governor Andrey Vorobyov said.
Elsewhere, a Russian strike on an apartment block in southeastern Ukraine Saturday killed a three-month-old baby and wounded 11 people, local officials said.
Drones hit the building in the town of Marhanets, said Oleksandr Hanzha, head of the Dnipropetrovsk Regional Military Administration.
Meanwhile, hundreds of mourners gathered in Kyiv at a memorial ceremony dedicated to three-year-old Dmytro Kucher and his grandparents, Halyna and Petro Kucher, who were killed by a Russian drone strike on August 8.
Multiple Russian drones destroyed the family's home in the Brovary district, northeast of Kyiv.
An initial ceremony was held at Kyiv's Spaskyi Lyceum, where Halyna had served as school principal for more than 20 years, before moving to a churchyard in the suburb of Zazymia, close to the former family home.
The couple's son, Oleksandr Kucher, said that his parents had been together since the fifth grade.
"They died together," he said.
"The Shahed (drone) completely tore my mother apart. We recovered only about two kilograms (about 4.4 pounds) of her remains."
He described his three-year-old son, Dmytro, as "our little miracle" and "the soul of our family".
"He kept my parents, me and our entire family going," Kucher said.
Russia's Ministry of Defence also said on Saturday that it had targeted warehouses and infrastructure at the Ukrainian ports of Odesa, Izmail and Yuzhnyi.
Ukraine's Air Force said that Russia launched 152 drones over the country Saturday, of which 124 were destroyed.
