(Reuters) – A senior Ukrainian official suggested a series of explosions at a Russian air base in Crimea could have been the work of partisan saboteurs, as Kyiv denied any responsibility for the incident deep inside Russian-occupied territory. The adviser to President Volodymyr Zelenskiy also suggested Russian incompetence as a possible cause of Tuesday’s blasts. They killed one civilian and injured eight, according to the health department in Russia-annexed Crimea. Huge plumes of smoke could be seen in videos posted on social media from Crimea, a holiday destination for many Russians. Russia …