Air raids by U.S. coalition warplanes have intensified in recent days as Kurdish and Arab militias seek to drive surrounded Islamic State militants from their last strongholds in Syria's Raqqa — but the toll on civilians has been severe.
Hundreds of civilians fled the city on Thursday, many wounded and malnourished after being trapped for months by fighting between Islamic State and the U.S.-backed Syrian Democratic Forces (SDF).
Those who fled said the sheer intensity of the bombardment appeared to have made militants shift their positions, retreat or hide underground, giving civilians a window in which to escape.