Ukraine pushes Russian forces back

Ukrainian forces reported battlefield gains on Wednesday in a counterattack that could signal a shift in the momentum of the war, while Kyiv shut gas flows on a route through Russian-held territory, raising the spectre of an energy crisis in Europe.  

Following days of advances north and east of the second largest city Kharkiv, Ukrainian forces were within just several kilometres of the Russian border on Wednesday morning, one Ukrainian military source said on condition on anonymity. Before the advance, Russian forces had been on the outskirts of Kharkiv, 40 km (25 miles) from the border.   The gains appear to be the fastest that Ukraine has achieved since it drove Russian troops away from Kyiv and out of the country’s north at the beginning of April. If sustained, it could let Ukrainian forces threaten supply lines for Russia’s main attack force, and even put rear logistics targets within Russia itself within striking range of Ukrainian artillery.   Kyiv has so far confirmed few details about its advance through the Kharkiv region, maintaining secrecy about the positions of its own forces near the frontline while speaking in general terms about overall gains.  
KYIV/VILHIVKA, Ukraine, May 11 (Reuters) -