Sirens sounded for 70 seconds in a number of Palestinian cities on May 15, marking the 70th anniversary of Palestinian Nakba, according to local reports.Nakba Day marks the anniversary of the displacement of 750,000 Palestinians during the 1948 Palestine War.This video was shared by Quds News Network. In the video a siren can heard ringing out in the West Bank. Credit: Quds News Network via Storyful