KYIV, Ukraine (AP) — A Russian drone strike on the city of Sumy in northeastern Ukraine killed three members of the same family, including a 13-year-old boy, while a Ukrainian strike on a Russian industrial plant killed five people, officials said Monday.

Russia has pounded civilian areas of Ukraine with drones and missiles since its all-out invasion more than four years ago. Ukraine increasingly has struck back against oil facilities and military factories deep inside Russia.

READ MORE: Russia strikes an apartment block in Ukraine's city of Kharkiv, killing 1 person

A United Nations tally says more than 16,000 civilians have died in the war. U.S.-led peace efforts have failed to stop the fighting.

The Sumy attack hit a home and killed a 36-year-old man, his son and the 73-year-old mother of his partner, according to Oleh Hryhorov, the head of the regional military administration. The man's partner and 10-year-old son were wounded, he said.

"An ordinary home — not a military target whatsoever," Ukrainian President Volodymyr Zelenskyy said on X.

The Ukrainian missile attack on the industrial plant in Voronezh in southwestern Russia killed five people and injured dozens, Gov. Alexander Gusev said. He did not name the plant.

Ukraine's General Staff said it hit a Voronezh factory that produces electronic parts for Russian missile and air defense systems.

Ukraine's monthly civilian casualties are highest in 4 years

The number of civilian casualties in Russian attacks has jumped recently, according to the U.N. Human Rights Monitoring Mission in Ukraine, as Moscow's forces struggle to gain momentum on the battlefield.

At least 274 civilians were killed and 1,763 injured in Ukraine in May, the highest monthly total of civilian casualties since April 2022, the mission said earlier this month. Most casualties are in cities far from the front line, it said.

A Russian nighttime drone strike killed a woman and wounded three people, including an 11-year-old boy, in the southeastern Ukrainian city of Zaporizhzhia, regional head Ivan Fedorov said.

Russia launched 88 long-range attack drones and one ballistic missile overnight, Ukraine's air force said, with air defenses shooting down or jamming 79 of the drones.

The Russian Defense Ministry said its forces intercepted 301 Ukrainian drones during the night over multiple Russian regions, the Crimea peninsula, the Azov Sea and the Black Sea.

Moscow Mayor Sergei Sobyanin said 84 Ukrainian drones targeting the Russian capital were shot down. He didn't mention any damage, but all four Moscow airports temporarily halted flights.

The success of Ukraine's long-range campaign against oil facilities, military transport and infrastructure has prompted Russian-held Crimea to halt civilian gasoline sales.

And all summer camps in illegally annexed Crimea on Monday stopped accepting children and new bookings until Sept. 1 for security reasons, said the Russian-installed governor of the occupied peninsula, Sergei Aksyonov.