By ADAM SCHRECK and ANDREA ROSA
ANDRIIVKA, Ukraine (AP) — The mayor of the besieged port city of Mariupol has put the number of civilians killed there at more than 5,000. Meanwhile, Ukraine continues to gather evidence of Russian atrocities and braces for what could become a climactic battle for control of the country’s industrial east. A U.S. defense official says Russia has completed the pullout of all of its estimated 24,000 or more troops from the Kyiv and Chernihiv areas in the north. At the United Nations, the U.S. and the United Kingdom boycotted an informal meeting of the Security Council called by Russia to press its baseless claims that the U.S. has biological warfare laboratories in Ukraine.