Crimea's Moscow-installed leader says four people killed in drone attack on the Russian-occupied Black Sea peninsula.

Ukrainian forces hit four gas compressors in Russian-occupied Crimea and an oil refinery in the Siberian city of Tyumen on June 20.

Footage of fires at a major depot on Crimea is circulating on social media. The Moscow-aligned governor of Crimea has halted public fuel sales after the attack.