KYIV, Ukraine (AP) — A young man shot a Russian military commander at close range at an enlistment office Monday. It was an unusually bold attack reflecting growing resistance to Russian President Vladimir Putin’s efforts to mobilize hundreds of thousands of more men to wage war on Ukraine. The shooting comes after scattered arson attacks on enlistment offices and protests in Russian cities that resulted in at least 2,000 arrests. Russia is seeking to bolster its military as its Ukraine offensive has bogged down. Concerns are growing that Russia may escalate the conflict — including potentially using nuclear weapons. Votes were being held, meanwhile, in four occupied Ukraine regions about joining up with Russia. Britain’s Foreign Secretary called the votes “sham referendums held at the barrel of a gun.”