Russia and Ukraine have exchanged airstrikes, following a week of intensified rhetoric in which Russia tested a new missile on Ukraine.
Russia has carried out nearly 1,500 strikes against Ukraine since Sunday evening on about half of the country's regions, wounding dozens, Ukrainian President Volodymyr Zelensky said.
Meanwhile, Ukraine's military said it had struck a key oil depot south of Moscow as well as targets in the border regions of Bryansk and Kursk.
Russia's use of the Oreshnik intermediate-range ballistic missile on the Ukrainian town of Dnipro capped a week of escalation in the war that also saw Ukraine fire US and British missiles at Russia for the first time.
US President Joe Biden has reportedly authorized Ukraine to use longer-range Atacms missiles against targets in Russia in response to Moscow's use of North Korean troops.
Kharkiv Governor Oleh Synehubov said 23 people were injured in a missile strike on the city of Kharkiv, where a rescue operation was currently underway.
An S-400 missile was used in the attack, he said.
Odessa's emergency service said 10 people were injured in a missile attack, which damaged residential buildings, schools and a university sports hall.
Regional officials said three more people were injured in strikes in the Kherson region, as well as one each in the Zaporizhzhya and Chernihiv regions.
Meanwhile, the Ukrainian military said it struck overnight with drones the Kaluganefteprodukt oil depot in the Kaluga region, southeast of Moscow.
Sources told Ukrainian media that the attack caused a series of explosions and a fire at the site.
The Russian military made no comment on the attack, but regional governor Vladislav Shapsha said debris from drones shot down by air defense caused “a fire on the territory of an industrial enterprise.” In total, eight drones were destroyed, he added.
The Ukrainian army also mentioned attacks in the Bryansk and Kursk regions, without specifying who the victims were.
However, Russian military bloggers said the Khalino air base in the Kursk region was hit in an attack by eight US-supplied Atacms missiles.
Thick cloud cover obscured satellite photos of the airfield on Monday, preventing verification of claims that it was hit in the nighttime strikes.
Footage posted on social media – showing bright flashes in the sky above the border region – purported to show the moment Ukrainian Atacms missiles were intercepted by Russian air defenses elsewhere in the Kursk region. Sound explosions could also be heard in the video.
Although BBC Verify has corroborated that the footage is authentic and filmed in the city of Kursk, it could not be established whether the strikes using the US-supplied missiles were behind the flashes seen based on the footage alone.
American authorization to use Atacms would be limited to this region due to the presence of North Korean troops.
They are believed to be involved in a Russian offensive aimed at driving Ukrainian forces from a small area of the Kursk region, which they captured in the fall in a surprise attack.
The Russian Defense Ministry only said it had shot down eight ballistic missiles from Ukraine, without specifying where.
Russian forces have also hit Ukraine's energy infrastructure in a bid to create harsh conditions as winter approaches.
Russia launched a full-scale invasion of Ukraine in February 2022. Both countries are now trying to secure a battlefield advantage before Donald Trump becomes US president in January and seeks to end the conflict.
He pledged to end the war within hours, but did not provide details on how to do so.
Additional reporting by Thomas Spencer.
