Hopes that a 72-hour cease-fire might lead to a formal cessation of hostilities were dashed Friday when Gaza militants fired rockets into Israel, which responded with strikes on targets inside the Palestinian enclave.
The breakdown was not entirely unexpected, as Hamas had warned it would not extend the cease-fire because Israel had not responded to any of the Palestinian demands.
Chief among them is Hamas' insistence that Israel end its 7-year blockade of Gaza and allow normal trade and traffic into the Mediterranean seaside territory that is home to 1.8 million people. Israel maintains it is willing to consider easing border restrictions but wants Hamas to disarm.
It was not immediately clear whether the end of the cease-fire also means an end to brokered talks between the two sides in Egypt.
Hamas officials said they were willing to continue negotiations, but an Israeli government official, speaking on condition of anonymity in line with government regulations, said Israel would not conduct negotiations under fire and would protect its citizens by all means.
The Israeli delegation left Cairo on Friday morning, and it was not clear if it would return.
Although fighting had resumed, it did not immediately rise to the level of violence that has marked the month-long conflict.
By midday, 33 rockets had been fired from Gaza, with 26 landing in Israel, injuring two people. Three were intercepted and four fell short in Gaza, the Israeli army said.
Israel launched at least 10 airstrikes in response to rocket and mortar fire from Gaza. One hit the backyard of a mosque and killed a 10-year-old boy, Palestinian officials said.
The Israel Defense Force announced that it was striking "terror sites across the Gaza Strip" in response to renewed rocket fire from Hamas.
Some 40,000 Gazan homes have been damaged or destroyed during the latest fighting that has displaced nearly half a million Palestinians and killed nearly 1,900 — more than 400 of them children, according to Gaza's Public Works Ministry and Health Ministry.
Israel's military says more than 60 of its soldiers, as well as a few civilians, have been killed in the fighting.