Zelenskyy warns of new offensive in east, says tens of thousands dead in Mariupol

Ukrainian President Volodymyr Zelenskyy has warned of a ramped-up Russian offensive in his country's east, with civilians rushing to flee the region ahead of what many fear could be a brutal new phase in the war.

Russia has deployed tens of thousands of troops to "prepare new attacks," Zelenskyy warned on Monday, a day after he vowed his country's troops were prepared to "respond" to the fresh assault Moscow's forces appeared poised to launch in eastern Ukraine.

Satellite images captured by Maxar, a commercial firm that works with the U.S. government, appeared to...