Six people have been killed and four injured in Ukrainian missile strikes on Russia's Belgorod region overnight, its acting governor has said.

A 14-year-old child was among those injured, Alexander Shuvaev wrote on Telegram on Monday.

Ukraine officials said two people were killed in Russian drone strikes overnight on the Sumy region, close to the border with Russia, which has been under frequent attack.

The strikes come a night after what Russian officials called the "largest-scale" attack launched by Ukraine this year, in which at least seven people were killed. Russian attacks on Ukraine also killed at least seven peopleand injured more than 39 on Saturday night.

Russia launched its full-scale invasion of Ukraine in February 2022 and currently controls approximately a fifth of Ukrainian territory.

The latest Ukrainian strikes burned a building and damaged a car in the village of Koloskovo in the Valuysky district, which is close to Russia's border with Ukraine, Shuvaev said.

The injured child was sent to hospital while two others received medical assistance, he added.

Meanwhile, a woman was killed after a drone strike hit a home in Russia's southern Astrakhan region, the local governor said on Monday.

Igor Babushkin wrote on Telegram that the Ukrainian strike targeted an industrial facility but that it had not been damaged.

In Ukraine, an overnight attack on the Black Sea port city of Odesa damaged a civilian vessel and injured four people, according to the regional head Oleh Kiper.

Moscow has sought to put off foreign companies from trading with Ukraine by targeting its ports and coastline.

Kyiv has stepped up drone strikes deep inside Russia during the past few weeks.

On Saturday night, Ukraine fired some 822 drones towards Russia, with 600 aiming for Moscow, according to its regional governor, who said the Russian capital suffered "one of the most massive drone attacks in recent memory".

During the strikes on Saturday night, five people died in Russia's south-western region of Rostov, its governor said. A woman was killed in an attack on a civilian bus in Belgorod, officials said, while an 83-year-old man died in a drone attack in the Moscow region.

A warehouse belonging to Russian online retailer Wildberries was also hit.

Since July, Ukraine has repeatedly targeted the company, known as Russia's version of Amazon. Ukraine's defence ministry said the latest attack meant that seven out of 10 of the largest Wildberries logistics centres had been "disabled".

Speaking to the BBC before the latest attacks, the deputy chief of Ukraine's intelligence service said long-range strikes in Russia would continue.

Maj Gen Vadym Skibitski defended Ukrainian attacks on distribution warehouses such as Wildberries and accused Russia of using civilian networks to supply its armed forces.

"It's one of the elements of the logistics system of the Russian Federation to wage the war, including through Wildberries - some military equipment, components and other elements," he said.

Skibitski said Ukraine did not deliberately target civilians, adding that some deaths in Russia were the accidental result of air defences shooting down incoming missiles and drones.

He claimed that drone strikes were influencing opinion among Russia's population, with concerns over the country's capability to "prevent" attacks and "to protect some areas".

Russia has also intensified missile attacks across Ukraine in recent weeks.

The Ukrainian energy company Naftogaz said on Monday that Russia had attacked its facilities 13 times during the past week.

In Russian attacks on Ukraine on Saturday night, a man and woman died after a private house was hit by a guided aerial bomb in the Zaporizhzhia region, officials said. Five others were killed in attacks across the country.

Russia said its attacks on Kyiv on Saturday night targeted a FirePoint facility producing parts for Ukrainian Flamingo missiles and a factory making components for drones.

The Russian attacks also hit a book market in the city's Pochayna district. Burnt books could be seen on the ground.

Ukrainian President Volodymyr Zelensky said 13 regions had come under attack this week, with Russia launching more than 1,550 attack drones, nearly 1,560 guided aerial bombs and 62 missiles.

Both sides accuse each other of targeting civilians.