Russia-Ukraine New War Updates: Russian troops left the heavily contaminated Chernobyl nuclear site early Friday after returning control to the Ukrainians, authorities said, as eastern parts of the country braced for renewed attacks and Russians blocked another aid mission to the besieged port city of Mariupol.Russia-Ukraine New War Updates: Russian troops left the heavily contaminated Chernobyl nuclear site early Friday after returning control to the Ukrainians, authorities said, as eastern parts of the country braced for renewed attacks and Russians blocked another aid mission to the besieged port city of Mariupol.