Moscow: At least 19 people were killed Sunday in drone and missile strikes in Russia and Ukraine which destroyed a book market in Kyiv while Moscow faced one of the most massive attacks since the start of the war. Ukraine and Russia have been escalating their long-range strikes for months, resulting in a growing number of civilian casualties, more than four years after the start of the Russian invasion.

According to France24.com, strikes killed 19 people in Russia and Ukraine, authorities said Sunday, as waves of drones and missiles pummelled civilian infrastructure on both sides.

With fighting at the front at a near standstill and talks frozen, the warring countries have significantly stepped up long-range attacks deep behind each other's lines, pushing the civilian death toll to its highest levels since the war's first months in 2022.

In Russia, swarms of Ukrainian drones killed five people in a residential area of the southern Rostov region, regional governor Yuri Slusar said.

Three more people were killed in the Belgorod, Kursk, and Moscow regions, along with four others in parts of Ukraine occupied by Russia.

Moscow's regional governor Andrey Vorobyov described the assault as "one of the most massive drone attacks in recent memory". Russia's defense ministry said it had intercepted 822 drones across the country overnight.

In Ukraine, a barrage of Russian drones and missiles killed two people and wounded 14 at ArcelorMittal's steel plant in Kryvyi Rih, President Volodymyr Zelensky's hometown.

The plant, one of Ukraine's biggest steel producers, said it partially halted operations after the strike damaged its core production facilities. Another strike hit Kryvyi Rih on Sunday evening, killing one person.

Strikes also hit other regions, killing two people in the southeastern Zaporizhzhia region, one in the border region of Sumy, and another in Donetsk in the east.

In Kyiv, a popular outdoor book market at Pochaina, long the place to find rare and antiquarian volumes, was struck. Bookseller Dmytro Semenukha saw all four of his stalls burn to the ground.

In a social media post on the overnight raid, Zelensky said that "wherever the Russians can reach with their ballistic missiles, they strike civilian infrastructure".

Over the past week, he said, Ukrainian cities had been pummelled by "more than 1,550 attack drones, nearly 1,560 guided aerial bombs, and 62 missiles", as he renewed his appeal to allies for more air defense.

Russia has carried out near-daily missile and drone strikes across Ukraine since launching its full-scale invasion in early 2022.

It has recently intensified attacks using hard-to-intercept ballistic missiles, exploiting Ukraine's air-defense shortages after the US-Israeli war against Iran diverted supplies.

Kyiv has recently renewed claims that Moscow is receiving more missiles and troops from its ally North Korea.

Countries bordering the conflict have faced increasing spillover from the drone war. After the overnight raid, Romania's defense ministry said a Spanish F-18 fighter jet had shot down a drone that breached its airspace near the borders with Ukraine and Moldova.

NATO said Friday its fighter jets had shot down a drone that entered Latvian airspace - the second such incident there in a week, according to Latvia's defense ministry.

For its part, Ukraine has increasingly targeted warehouses belonging to Russia's biggest online retailer Wildberries, saying the company supplies components for Russian drones.

Near Moscow, another Wildberries warehouse was set ablaze by Ukrainian drones overnight. Since mid-July, Ukraine has struck around 20 warehouses and buildings linked to the company.

Zelensky says those strikes, along with attacks on oil refineries, are aimed at undermining Russia's war economy.

In July alone, 437 civilians were killed in Ukraine, the highest monthly toll since May 2022, according to a United Nations tally.

Russian authorities have reported 79 civilians killed on their side in July, up from the previous month.