TOPSHOTS Ukrainian people attend a memorial ceremony for the 28th anniversary of the Chernobyl disaster, which was the world's worst nuclear accident, outside a regional administration building they seized in the in the eastern Ukrainian city of Slavyansk on April 25, 2014. Russia Foreign Minister Sergei Lavrov accused the United States of seeking to smear Moscow and called US Secretary of State John Kerry's tone over the Ukraine crisis unacceptable. AFP PHOTO/KIRILL KUDRYAVTSEV