At least 119 Palestinians, including 31 children, have been killed and more than 830 injured since hostilities began on Monday.
Hundreds of Palestinian families have taken refuge in UN-run schools in northern Gaza to flee Israeli artillery fire.
Israeli artillery and tank shells fired in Gaza on Thursday evening forced many families to flee their homes. The Palestinians marked the first day of the religious holiday of Eid al-Fitr under relentless aerial bombardment.
At least seven Israelis and an Indian citizen have also been killed. The Israeli military said hundreds of rockets were fired from Gaza into Israel.
Israel mustered additional soldiers and tanks near Gaza and Israel’s defense minister approved the mobilization of 9,000 more reserve troops. But the armed forces maintained a ground offensive that was not the main focus of the operation against Palestinian fighters.