KYIV, Ukraine — A Russian-guided bomb exploded next to public buses filled with passengers in eastern Ukraine, authorities said Thursday, killing 30 people as part of a wave of attacks that also worsened power outages in the capital. The morning attack occurred next to a bus stop in the war-torn city of Kramatorsk in Ukraine’s Donetsk region, prompting public transport to be suspended in the area. “There is no doubt that Russia is cynically targeting civilians,” Oleksandr Honcharenko, head of the city's military administration, said, adding that the rescue effort had been hampered by subsequent Russian attacks using small drones. Russia and Ukraine are locked in a long-range aerial war while their armies remain largely deadlocked on the front line, more than 4 1/2 years since Moscow’s full-scale invasion. Russia has escalated its aerial attack in recent weeks, putting pressure on Ukraine as it prepares for winter and hitting the infrastructure keeping its war-battered economy afloat. Recent targets have included energy systems, key industries, railways, post offices, shopping