A Ukrainian drone attack caused a fire on an oil tanker berthed in the port of Tuapse on the Black Sea, civil protection authorities in the southern Russian region of Krasnodar reported on Sunday.
The attack also damaged the oil transfer terminal, they said. The tanker's crew was evacuated.
Photos published on the Telegram messaging service indicated three fires in the port, which lies south-east of the Crimean Peninsula.
The civil protection authorities later added that two civilian ships flying foreign flags had also been damaged, without providing further details. They said debris from Ukrainian drones also fell on other port cities on Russia's Black Sea coast.
Novorossiysk to the north-west and Tuapse are the most important Black Sea ports for Russian oil exports. Ukrainian forces have for months been targeting Russian oil infrastructure essential for funding the war.
Large Ukrainian drone attacks were also reported in other parts of Russia. Two people were injured in the Rostov region lying to the east of Ukraine, authorities reported.
The Russian Defence Ministry in Moscow reported intercepting 164 Ukrainian drones overnight.
In Ukraine, four people, including two children, were killed by a Russian drone attack in the Dnipropetrovsk region in the east of the country, according to a report on Telegram from Vladyslav Hayvanenko, the regional governor.
Two people were killed and two others injured in the Black Sea region of Odessa, officials said.
Drone attacks were also reported in Zaporizhzhya in the south and Chernihiv in the north.
Major power outages affecting tens of thousands of households were reported in Chernihiv, Zaporizhzhya and the Donetsk region after the airstrikes.
Ukrainian President Volodymyr Zelensky said Russia has used nearly 1,500 combat drones, 1,170 guided bombs and more than 70 missiles against Ukraine this week alone.
"There were hits on ordinary residential buildings and civilian infrastructure, as well as numerous terrorist attacks targeting the energy sector," he wrote in a post on X on Sunday.
Zelensky said Russia wants to harm the people of Ukraine, but the government in Kiev is working to secure energy supplies for the approaching winter.
The Ukrainian president thanked his foreign partners who are helping to protect the country's energy system, including Germany, the United States and the European Union.
Ukraine has been warding off a full-scale Russian invasion since February 2022.
