Blasts rocked a Russian air base near seaside resorts in the annexed Crimea, injuring five people according to local authorities in what Moscow attributed to detonations in ammunition stories.

Russia’s defence ministry said the “detonation of several aviation ammunition stores” had caused an explosion, Russian news agencies reported, but that there had been no injuries.

The ministry added there had not been any kind of attack and that no aviation equipment had been damaged. Moscow said further measures were being taken to establish the causes.

No comment was immediately available from Ukraine.