Huge Russian convoy advances on Kyiv, which braces for a siege

KYIV, Ukraine — Russian forces continued to batter targets in Ukraine on Tuesday, striking the embattled nation’s second-largest city, Kharkiv, and assembling a 40-mile-long column of tanks, artillery and other military vehicles outside the capital, Kyiv, in what could be a sign of an imminent assault.

The specter of more violence and the scenes of civilians huddled in bomb shelters or pouring across Ukraine’s western borders come as Russia finds itself increasingly isolated on the world stage, with sanctions inflicting immediate damage to its economy and currency. The United Nations’ refugee agency reported that 660,000 people have fled Ukraine in the last six days — a rate that puts the situation on track to “become Europe’s largest refugee crisis this century,” agency spokesperson