A mother and her 9-year-old son have been killed in Russian drone strikes on Ukraine's border region of Sumy, the head of the local military administration, Oleh Hryhorov, said on Friday.
Two drones set a private house on fire and destroyed it, killing the 29-year-old mother and her son, Hryhorov said on Telegram.
Four other people were injured, including the boy's father and grandmother, who were taken to hospital with severe burns.
In the city of Smila in central Ukraine, five people were injured in a Russian drone strike, the Cherkasy regional prosecutor's office said. The authority described a massive attack on civilian infrastructure.
Ukrainian President Volodymyr Zelensky called for pressure on companies to ensure supply chains for foreign components are cut. Russia uses around 220 glide bombs a day against frontline communities, which it produces and adapts despite sanctions, he wrote.
In a Telegram post on Friday, the Russian Defence Ministry threatened to freeze Ukraine in winter.
"You'll be frozen out this winter," it posted below an imaged of flying drones.
Last winter, Moscow carried out massive attacks on Ukraine's energy supply, leaving millions of Ukrainian without electricity, water and heating in sub-zero temperatures.
The Ukrainian military responded with an image of a column of smoke over an oil facility in Russia.
"We will warm ourselves at the fire of Russian refineries," it said.
Meanwhile, Ukrainian forces continued their counterstrikes against Russia. Governor Aleksandr Drozdenko said 51 drones were intercepted over the Leningrad region which surrounds St Petersburg, after which a fire broke out at the port of Ust-Luga.
He said the damage caused by the drone strike was quickly repaired. The Baltic port of Ust-Luga is an important export hub for liquefied gas, fertilizer and coal, and has been targeted by Ukrainian strikes on several previous occasions.
Authorities in the Tver region, north-west of Moscow, also reported damage. Falling drone debris damaged the wall of a warehouse belonging to online retailer Wildberries. No injuries were reported.
Russia has been waging a full-scale war against Ukraine for nearly four and a half years. In its defence, Kiev has relied heavily on drone strikes on Russian territory.