At least 12 people were killed and 14 others wounded on Thursday when Russia struck two passenger buses in Kramatorsk near the frontline in eastern Ukraine, authorities said. "According to preliminary data, 12 people are known to have been killed as of now. Additionally, 14 people are believed to have sustained injuries," the local prosecutor's office said. "The final toll of the enemy attack is being determined," it added, posting photos of bodies and debris strewn across a road in front of the burning metal shell of a bus. Ukraine's national police said Russia had hit the buses with a glide bomb. Kramatorsk is one of the key cities that Russia has not yet captured in the eastern Donetsk region, which Moscow claims as its own. It has been a logistics and supply hub for the Ukrainian military for much of the war and is part of the so-called "fortress belt" which troops are fighting to keep hold of. Russian forces have edged close to the city's eastern edge, which has prompted calls for civilians who remain to relocate to safer regions of Ukraine. Thursday's strike, which happened at 10:00 am (0700 GMT), came a day after a Russian missile hit an apartment block in the northern region of Chernigiv, killing 22, including five children. Kramatorsk City Council said it was "yet another horrific crime committed by the Russian army against the civilian population". "Once again, the Russians have struck a location where there are absolutely no military targets," it added.