The Russian Defense Ministry said there were no “serious” casualties in the Mayskoye explosion, state news agency RIA reported. Earlier on Tuesday, RIA also reported a fire at a transformer substation near the city of Dzhankoi in Crimea, 20 kilometers (14 miles) away. read more Crimea, which has been under Russian control since 2014 even as most of the world recognizes it as Ukrainian territory, has been a major staging ground for the military campaign Russia launched in Ukraine on February 24. Sign up now for FREE unlimited access to Reuters.com Register Ukraine has not officially confirmed or denied responsibility for the reported explosions in Crimea in recent days. “Reminder: Crimea of a normal country is about the Black Sea, mountains, recreation and tourism, but Crimea occupied by Russians is about warehouse explosions and high risk of death for intruders and thieves,” the adviser to the Ukrainian president tweeted Mykhailo Podolyak after Tuesday’s explosions. Russian reports did not say how many explosions occurred in total. Last week, a series of explosions at a military air base in the city of Novofedorivka, on the western coast of Crimea, appeared to cause extensive damage and destroy several Russian military aircraft, according to commercial satellite images. Russia called the incident an accident. Sign up now for FREE unlimited access to Reuters.com Register Edited by Christian Schmollinger and Peter Graff Our Standards: The Thomson Reuters Trust Principles.