A high-ranking Russian naval officer from the Black Sea Fleet has been killed in a car explosion in Sevastopol on the Crimean Peninsula, media reports say. Ukrainian media said he was commander of a missile ship brigade, citing a source in the Kiev security service SBU, which is said to be behind the killing. According to the Russian state news agency TASS, the car blast was presumably due to an explosive device placed under the vehicle and Russian authorities are therefore investigating a terrorist attack. Ukraine has been defending itself against a large-scale Russian invasion for more than …