Mideast Israel Palestinians(01 of17)
Open Image ModalDisplaced Palestinians seek refuge in a United Nations school in Gaza City after fleeing their homes Sunday, July 13, 2014. Israel has called on residents of the northern Gaza Strip to evacuate their homes, suggesting a coming attack after its troops earlier launched a brief raid. (AP Photo/Khalil Hamra) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(02 of17)
Open Image ModalDisplaced Palestinians seek refuge in a United Nations school in Gaza City after fleeing their homes Sunday, July 13, 2014. Israel has called on residents of the northern Gaza Strip to evacuate their homes, suggesting a coming attack after its troops earlier launched a brief raid. (AP Photo/Khalil Hamra) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(03 of17)
Open Image ModalAn elderly Palestinian takes shelter at the United Nations school after his family fled their homes in Gaza City on Sunday, July 13, 2014. Israel briefly deployed ground troops inside the Gaza Strip for the first time early Sunday as its military warned northern Gaza residents to evacuate their homes, part of a widening offensive that has killed more than 160 Palestinians. (AP Photo/Adel Hana) (credit:ASSOCIATED PRESS)
APTOPIX Mideast Israel Palestinians(04 of17)
Open Image ModalPalestinians drive past a building destroyed by an Israeli strike on Friday, in Gaza City, Sunday, July 13, 2014. Thousands of Palestinian residents of the northern Gaza Strip fled their homes on Sunday and sought safety in U.N. shelters, heeding warnings from the Israeli military about impending plans to bomb the area in the sixth day of an offensive against Hamas that has killed more than 160 people. (AP Photo/Lefteris Pitarakis) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(05 of17)
Open Image ModalPalestinians flee their homes to take shelter at the United Nations school in Gaza City, Sunday, July 13, 2014. Israel briefly deployed ground troops inside the Gaza Strip for the first time early Sunday as its military warned northern residents to evacuate their homes, part of a widening campaign against militant rocket fire that\'s seen more than 160 Palestinians killed. Israel accuses Hamas of using Gaza\'s civilians as human shields by firing rockets from there. Critics say Israel\'s heavy bombardment of one of the most densely populated territories in the world is itself the main factor putting civilians at risk. (AP Photo/Hatem Moussa) (credit:ASSOCIATED PRESS)
APTOPIX Mideast Israel Palestinians(06 of17)
Open Image ModalPalestinians flee their homes to take shelter at the United Nations school in Gaza City, Sunday, July 13, 2014. Israel briefly deployed ground troops inside the Gaza Strip for the first time early Sunday as its military warned northern residents to evacuate their homes, part of a widening campaign against militant rocket fire that\'s seen more than 160 Palestinians killed. Israel accuses Hamas of using Gaza\'s civilians as human shields by firing rockets from there. Critics say Israel\'s heavy bombardment of one of the most densely populated territories in the world is itself the main factor putting civilians at risk. (AP Photo/Hatem Moussa) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(07 of17)
Open Image ModalPalestinians take shelter at the United Nations school after they fled their homes in Gaza City on Sunday, July 13, 2014. Israel briefly deployed ground troops inside the Gaza Strip for the first time early Sunday as its military warned northern Gaza residents to evacuate their homes, part of a widening offensive that has killed more than 160 Palestinians. (AP Photo/Adel Hana) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(08 of17)
Open Image ModalPalestinians take shelter at the United Nations school after they fled their homes in Gaza City, Sunday, July 13, 2014. Israel briefly deployed ground troops inside the Gaza Strip for the first time early Sunday as its military warned northern Gaza residents to evacuate their homes, part of a widening offensive that has killed more than 160 Palestinians. (AP Photo/Adel Hana) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(09 of17)
Open Image ModalPalestinians take shelter at the United Nations school after they fled their homes in Gaza City on Sunday, July 13, 2014. Israel briefly deployed ground troops inside the Gaza Strip for the first time early Sunday as its military warned northern Gaza residents to evacuate their homes, part of a widening offensive that has killed more than 160 Palestinians. (AP Photo/Adel Hana) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(10 of17)
Open Image ModalPalestinians flee their homes to take shelter at the United Nations school, in Gaza City, Sunday, July 13, 2014. Israel briefly deployed ground troops inside the Gaza Strip for the first time early Sunday as its military warned northern residents to evacuate their homes, part of a widening campaign against militant rocket fire that\'s seen more than 160 Palestinians killed. Israel accuses Hamas of using Gaza\'s civilians as human shields by firing rockets from there. Critics say Israel\'s heavy bombardment of one of the most densely populated territories in the world is itself the main factor putting civilians at risk. (AP Photo/Hatem Moussa) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(11 of17)
Open Image ModalPalestinians flee their homes to take shelter at the United Nations school in Gaza City, Sunday, July 13, 2014. Israel briefly deployed ground troops inside the Gaza Strip for the first time early Sunday as its military warned northern residents to evacuate their homes, part of a widening campaign against militant rocket fire that\'s seen more than 160 Palestinians killed. Israel accuses Hamas of using Gaza\'s civilians as human shields by firing rockets from there. Critics say Israel\'s heavy bombardment of one of the most densely populated territories in the world is itself the main factor putting civilians at risk. (AP Photo/Hatem Moussa) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(12 of17)
Open Image ModalDisplaced Palestinians seek refuge at a United Nations school in Gaza City after fleeing their homes. Sunday, July 13, 2014. Israel has called on residents of the northern Gaza Strip to evacuate their homes, suggesting a coming attack after its troops earlier launched a brief raid. (AP Photo/Khalil Hamra) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(13 of17)
Open Image ModalPalestinians flee their homes to take shelter at the United Nations school in Gaza City, Sunday, July 13, 2014. Israel briefly deployed ground troops inside the Gaza Strip for the first time early Sunday as its military warned northern residents to evacuate their homes, part of a widening campaign against militant rocket fire that\'s seen more than 160 Palestinians killed. Israel accuses Hamas of using Gaza\'s civilians as human shields by firing rockets from there. Critics say Israel\'s heavy bombardment of one of the most densely populated territories in the world is itself the main factor putting civilians at risk. (AP Photo/Hatem Moussa) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(14 of17)
Open Image ModalDisplaced Palestinians seek refuge in a United Nations school in Gaza City after fleeing their homes Sunday, July 13, 2014. Israel has called on residents of the northern Gaza Strip to evacuate their homes, suggesting a coming attack after its troops earlier launched a brief raid. (AP Photo/Khalil Hamra) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(15 of17)
Open Image ModalDisplaced Palestinians seek refuge at a United Nations school in Gaza City after fleeing their homes. Sunday, July 13, 2014. Israel has called on residents of the northern Gaza Strip to evacuate their homes, suggesting a coming attack after its troops earlier launched a brief raid. (AP Photo/Khalil Hamra) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(16 of17)
Open Image ModalDisplaced Palestinians seek refuge in a United Nations school in Gaza City after fleeing their homes Sunday, July 13, 2014. Israel has called on residents of the northern Gaza Strip to evacuate their homes, suggesting a coming attack after its troops earlier launched a brief raid. (AP Photo/Khalil Hamra) (credit:ASSOCIATED PRESS)
Mideast Israel Palestinians(17 of17)
Open Image ModalDisplaced Palestinians seek refuge in a United Nations school in Gaza City after fleeing their homes Sunday, July 13, 2014. Israel has called on residents of the northern Gaza Strip to evacuate their homes, suggesting a coming attack after its troops earlier launched a brief raid. (AP Photo/Khalil Hamra) (credit:ASSOCIATED PRESS)