A huge fire broke out on Saturday at a fuel depot in Sevastopol, the main port in Crimea, with authorities saying it was the result of a drone attack, AFP reported.

Sevastopol is home to Russia's Black Sea Fleet and has been hit by a series of drone attacks since the Kremlin's Ukraine military operation launched last year.

"A fuel reserve is on fire in the Kazachya Bay district" of the city, the Moscow-installed governor of Sevastopol Mikhail Razvozhayev said on Telegram in the early hours of Saturday.

"According to preliminary information, it was caused by a drone strike."

He said the fire's size was "around 1,000 square meters" and published images of huge clouds of smoke rising into the air.

Razvozhayev called on Crimeans to "remain calm" and in a later post said, "Nobody was hurt."

He said authorities had "the situation under control" and said there was no threat to civilian infrastructure.

Earlier this week, Russia said it had repelled a drone attack on the port.