Russia has officially banned all diesel exports in a bid to secure its domestic fuel market following highly destructive Ukrainian drone strikes on its energy infrastructure. According to Deputy Prime Minister Alexander Novak, the embargo covers all diesel exports, closing a loophole that allowed self-producing oil firms to sell fuel abroad. The ban is scheduled to remain in place through the end of July. On Tuesday, a long-range Ukrainian strike successfully crippled Gazprom Neft’s Omsk oil refinery--Russia's largest fuel processing plant--knocking…