In what Russia called an “act of sabotage”, a fireball explosion ripped through the facility in Maiske, near Dzhankoi, on Tuesday morning, injuring at least two and prompting the evacuation of around 3,000 people. Ukraine has not claimed responsibility for the blasts in Crimea, which Russia seized in 2014 and has been used by Vladimir Putin to launch attacks since the start of the war on February 24. Worsening the outlook in Crimea was a report by the business newspaper Kommersant that explosions had also occurred near Gvardeyskoye in the center of the peninsula. As of Wednesday, there was still no comment from Russian authorities. A statement from Britain’s Ministry of Defense on Wednesday said that “Russian commanders are very likely to be increasingly concerned about the apparent deterioration of security across Crimea, which serves as a rear base area for the occupation.” Smoke rises near Dzhankoi (REUTERS) It said that Gvardeyskoye and Dzhankoi “host two of the most important Russian military airfields in Crimea.” If Ukraine was behind the blasts, it would represent a major escalation of the war. Such attacks could also indicate that Ukrainian agents are able to penetrate deep into Russian-occupied territories. Last week, Mr Putin’s military in Crimea came under pressure after Ukraine said nine Russian warplanes were destroyed after explosions. At the time, Moscow still offered the possibility of a discarded cigarette butt as the cause. Meanwhile, in the Donetsk region on the front line of the Russian offensive, two civilians have been killed and seven others injured in recent Russian shelling of several towns and villages. Russian Tu-22M3 long-range bombers fired cruise missiles in the Odesa region on Tuesday night, injuring four people, according to Oleh Bratchuk, a spokesman for the Odesa regional administration. In the southern city of Mykolaiv, two Russian rockets damaged a university building early Wednesday, but no one was injured. Russian forces also shelled Kharkiv and various parts of the Kharkiv region overnight, damaging residential buildings and civilian infrastructure, but causing no casualties. On Thursday, UN Secretary-General Antonio Guterres plans to travel to Ukraine for a meeting in the western city of Lviv with Ukrainian President Volodymyr Zelensky and Turkish President Recep Tayyip Erdogan. They are expected to discuss grain shipments and a possible fact-finding mission to the Russian-controlled Zaporizhzhia nuclear power plant, which Russia and Ukraine have accused each other of bombing. Additional reporting by The Associated Press.