A drone was shot down over the headquarters of Russia’s Black Sea fleet in annexed Crimea on Saturday, a local official said.

“The drone was shot down just above the fleet headquarters” in the city of Sevastopol, city governor Mikhail Razvojaev wrote on Telegram, blaming the attempt on Ukrainian forces.

“It fell on the roof and caught fire,” he said, adding that there was no major damage or victims.

It was the second assault of its kind against the fleet headquarters in less than a month, after a drone attack on July 31 in its courtyard wounded five people and led to the cancellation of planned Fleet Day celebrations.

It was also the latest attack to target Russian military infrastructure in Crimea, a Black Sea peninsula that Moscow seized and annexed from Ukraine in 2014.

Also on Saturday, Konstantin Ivashchenko, appointed by pro-Russian forces as mayor of the port city of Mariupol in southeastern Ukraine, was the target of an assassination attempt, according to Russian news agencies.

An explosion rocked his car as it drove past a zoo, the RIA Novosti news agency quoted a police source as saying Ivashchenko “was not injured,” the source added.

Earlier Saturday, air defence systems were activated in Evpatoria in western Crimea.

Russian forces on Thursday shot down a drone near an air base in Sevastopol, just two days after explosions ripped through a military base and ammunition depot in Crimea.

In early August, a blast at the Saki air base killed one person and wounded several others. (AFP)