At least one person has been killed and three others wounded following overnight Russian strikes on the Odessa region in southern Ukraine, the region's governor said on Saturday.
Oleh Kiper said on Telegram that five grain transporters had been burned out and three others damaged. All fires were extinguished, he said.
Earlier, the administration of the Izmail district, where the country's Danube ports are located, had warned of Russian drones in the area. Transport infrastructure facilities were damaged, it said.
Several people were also killed on Friday evening near the village of Myla, around 5 kilometres west of the capital Kiev, after a fire triggered by explosions.
"We do not yet have sufficient information on the number of casualties," Kiev Governor Tymur Tkachenko wrote on Telegram.
The prosecutor's office opened an investigation into "negligence in the line of duty" and initially reported five people wounded following a possible drone strike. Russia said an ammunition depot was the target of the attack.
The main road connecting Kiev to the west had to be completely closed over a stretch of several kilometres to allow firefighting and rescue operations to take place. Videos on social media showed fire and explosions in the evening twilight.
Prime Minister Sergii Koretskyi pointed to a similar incident in early July on the south-western outskirts of Kiev. "In the fifth year of the war, the same mistakes are being made: This is criminal negligence," he wrote on Telegram.
At least two people were also wounded in Kiev itself, according to authorities. Ukraine has been defending itself against the Russian invasion for more than four and a half years.
Meanwhile, at least seven people have been wounded in a wave of Ukrainian airstrikes on the Rostov region in southern Russia, local authorities said on Saturday.
Two children were taken to hospital, one with very serious injuries, state news agency TASS reported, citing Governor Yuri Slyusar. Two residential blocks in the port city of Rostov-on-Don were damaged by falling drone debris, according to the report.
Ukrainian media reported that a warehouse belonging to an electronics retailer also caught fire.
The reports could not be independently verified.
For weeks, Ukrainian forces have repeatedly targeted the logistics centres of major Russian companies. Online retailers Wildberries and Ozon have been among the main targets.
The strikes have caused damage running into the billions and have brought renewed attention to the consequences of Russia's war on its neighbour. Kiev's leadership is also seeking to influence the political mood in Russia ahead of parliamentary elections scheduled for September 18 to 20.
Ukraine has been defending itself against Russia's destructive war for four and a half years with the help of Western military aid. Both sides deploy vast numbers of drones in their mutual strikes, as the weapons are relatively cheap to produce and difficult to intercept when deployed in large numbers.
During some attack waves, hundreds of drones are used simultaneously to overwhelm air defences. Both sides accuse each other of deliberately targeting civilians, though casualties and damage on the Ukrainian side are far greater.