The Russian-installed head of the city of Dzhankoi said the area had been attacked by drones.
Ukraine announced the explosions but, as is normal, did not explicitly say it was behind the attack.
If confirmed, it would be a rare foray by Ukraine's military into Crimea, which has been annexed since 2014.
The "mysterious" explosions destroyed Russian Kalibr-NK cruise missiles, intended for use by Russia's Black Sea Fleet, Ukrainian defence intelligence said. Kailbr missiles have been widely used in attacks on Ukrainian cities and infrastructure in recent months.
One unconfirmed report from a resident cited on Ukrainian TV spoke of "booms" that went on for 30 minutes, leaving part of Dzhankoi with no electricity. The blasts "continue the process of Russia's demilitarisation and prepares the Ukrainian peninsula of Crimea for de-occupation", the defence ministry said.