Ukrainians are widely expected to give a resounding endorsement to the overthrow of their last elected leader by voting for presidential candidates promising close ties with the West, in defiance of Russia's Vladimir Putin.
But the absence of more than 15 percent of the electorate, in Russian-annexed Crimea and two eastern regions where fighting with pro-Moscow rebels continued on Saturday, may mar any result.
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Uplifting messages greeted commuters on the London Underground a day after the terror attack in Westminster.
Faith leaders from across London say religious communities will "stand together" in the wake of the Westminster terror attack.
Pc Keith Palmer was among the three people killed yesterday in the Westminster terror attack.