SNAPSHOT-Russia's war on Ukraine latest: Wagner Group threatens to leave Bakhmut

* Engineers have reduced the risk of a dam bursting and damaging the large Russian-held Zaporizhzhia nuclear power station in Ukraine, a senior Russian official was quoted as saying by TASS news agency. QUOTES * "Because of the lack of ammunition, our losses are increasing exponentially every day," Wagner Group mercenary leader Yevgeny Prigozhin said. * "The colours give us an easier daily routine, because when everything is grey it's much harder to deal with," Olena Yukhymchuk, 37, said in a Kyiv park where pink cherry blossom contrasts with barbed wire and anti-tank barriers.

Russia's Wagner threatens to leave the eastern city of Bakhmut, but Ukraine says the mercenaries are reinforcing positions from other parts of the front to try to seize it before Moscow marks World War Two Victory Day next week. WAGNER GROUP

* Standing in a field of corpses, Russian Wagner Group boss Yevgeny Prigozhin published an expletive-ridden video personally blaming top defence chiefs for losses suffered by his fighters. * He said his forces would withdraw from Bakhmut on May 10 - ending their involvement in the longest and bloodiest battle of the war - because of heavy losses and inadequate supplies.

GRAIN * The pace of grain shipments from Ukraine under a U.N.-backed initiative has slowed as concerns grow over ships getting stuck if a deal is not renewed later this month, according to sources and data.

* Ukraine, Russia, Turkey and the United Nations failed to authorize any new ships under the deal. CONFLICT

* A drone attack on the Ilsky oil refinery in southern Russia, the second in as many days, has caused a fire, TASS news agency reported. * Engineers have reduced the risk of a dam bursting and damaging the large Russian-held Zaporizhzhia nuclear power station in Ukraine, a senior Russian official was quoted as saying by TASS news agency.

QUOTES * "Because of the lack of ammunition, our losses are increasing exponentially every day," Wagner Group mercenary leader Yevgeny Prigozhin said.

* "The colours give us an easier daily routine, because when everything is grey it's much harder to deal with," Olena Yukhymchuk, 37, said in a Kyiv park where pink cherry blossom contrasts with barbed wire and anti-tank barriers. RECENT IN-DEPTH STORIES

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* ANALYSIS-Kremlin incident gives Putin cover to deepen war * COLUMN-Global ammunition race may decide Ukraine war (Compiled by Reuters editors)