The attack came five days after the only bridge linking annexed Crimea to Russia was hit, killing two people.

Crimea, annexed by Moscow in 2014, has been targeted throughout Russia's Ukraine offensive but has come under increasing attack in recent weeks.

"As a result of an enemy drone on the Krasnogvardeisky district, there was a detonation at an ammunition depot," official Sergei Aksyonov said on Telegram.

"A decision was taken to evacuate people (living) within five kilometres" of the zone, he said.

He did not specify which location was hit, saying only it was in the Krasnogvardeisky district, which lies inland at the centre of the Black Sea peninsula.

Aksyonov also said train traffic will be stopped on the peninsula.

"To minimise risks, it was also decided to halt rail traffic on Crimean railways."

Authorities later said that two trains going from Moscow to Crimea's main city of Simferopol and one in the opposite direction had been stopped.

Attacks on the Black Sea peninsula have intensified in recent weeks, with Kyiv launching a counteroffensive to retake land lost to Moscow, and saying it also aims to reclaim Crimea.

Speaking remotely to the Aspen Security Forum on Friday, Ukrainian President Volodymyr Zelensky said Russia's Crimea bridge must be "neutralised."

He said the bridge, inaugurated by President Vladimir Putin in 2018, "supplies ammunition to the Crimean peninsula."

Kyiv considers the bridge an "enemy object" built in violation of international law.

Asked if Kyiv aims to return Crimea in its counteroffensive, Zelensky said:

"The goal is to return all of Crimea, because it is our sovereign state, and our sovereign territory is an integral part of our state."