Ukraine accused pro-Russian separatists of killing dozens of civilians by firing on a refugee convoy, the latest example of residents caught in the line of fire of a four-month-old war that has caused more than 2,000 deaths.

Rebels denied any role in the attack, or that an attack had taken place. The U.S. State Department condemned the "shelling and rocketing" of the convoy but said it couldn't confirm who was responsible.

...