Editor's note: This is a developing story and is being updated.Explosions and fires were reported overnight on May 27 across multiple regions in Russia and occupied Crimea, including in Tuapse, where an oil refinery was reportedly struck for the fifth time in a month. Monitoring channels reported that an oil refinery in Tuapse, located in Russia’s Krasnodar Krai along the Black Sea coast, was among the targets of the overnight strikes.The facility has been repeatedly targeted in recent months and was reportedly struck for at least the fifth time in the past month, according to open-source reports.Residents in Taganrog, located in Rostov Oblast, reported blasts and visible smoke across parts of the city, with preliminary reports suggesting a strike and subsequent fire at a facility involved in the maintenance and repair of aviation equipment.Taganrog sits along southern Russia's Azov Sea coast, located just 40 kilometers (25 miles) from Ukraine's border with Russia.Similar reports of an attack also emerged on Telegram from Voronezh, where residents said explosions were heard overnight, and smoke was seen rising over the city.According to independent Telegram channel Astra, the smoke was observed near the Baltimore military airfield, which hosts Russia’s 47th Guards Bomber Aviation Regiment and is regularly used to launch airstrikes against Ukraine.Voronezh Oblast Governor Alexander Gusev said that two “high-speed targets” were allegedly shot down by air defenses, adding that no casualties were reported, though falling debris damaged a tire repair shop and a utility building.Voronezh Oblast neighbors Ukraine's Kharkiv Oblast and is often used as a launch point for Russia's attack on the front line as well as the city of Kharkiv.Separately, Russian-installed authorities in occupied Sevastopol claimed that a bank building caught fire following a Ukrainian attack, allegedly involving Storm Shadow missiles, and that a nearby residential building sustained damage from the blast wave.The Kyiv Independent could not immediately verify the reports, and Ukraine’s military has not commented on the claims.Ukraine regularly strikes military infrastructure deep within Russia and occupied territories in an effort to diminish Moscow's capacity to continue waging war on Ukraine.