Israeli media said municipalities in the Tel Aviv area were reopening shelters they had shut when fighting subsided two weeks ago.
The violence also prompted a new exodus of dozens of Palestinian families who had fled previous fighting and had returned home only days ago.
A Palestinian delegate in Cairo said negotiations for a durable ceasefire were near collapse. "The talks have been suspended unofficially," said Qais Abdel Karim of the Popular Front for the Liberation of Palestine.
The Palestinians want Egypt and Israel to lift their blockades of the economically crippled Gaza Strip that predated the Israeli offensive.
Hamas leader Izzat al-Risheq told reporters at a Cairo hotel he believed chances of reaching another truce were "very weak". Risheq posted on Twitter that Egypt was awaiting an Israeli response before the truce officially expired.