SDEROT, ISRAEL - JULY 13:  Men take cover behind a car due to a rocket attack siren going off while watching Israeli attacks inside Gaza from the top of a hill on the sixth day of Israel's operation 'Protective Edge' on July 13, 2014 in Sderot, Israel. Hundreds of foreigners fled Gaza today as Israeli ground troops entered northern Gaza to take out missile launch sites. The IDF continues to carry out massive airstrikes across the Gaza Strip, which has so far killed more than 160 people, the majority of whom are civilians.  (Photo by Andrew Burton/Getty Images)