Israel's military has carried out air strikes in the Gaza Strip in response to Hamas rocket fire just hours before the latest ceasefire was set to expire.
Prime Minister Benjamin Netanyahu says the rocket attack was a grave and direct violation of the ceasefire.
Officials say three rockets landed near the town of Beersheba and two were intercepted near Netivot nearly eight hours before the temporary truce was due to expire. There were no injuries or damage.
Witnesses said Israeli aircraft carried out at least 25 strikes, and hospital officials reported that five Palestinians, two of them children, were wounded.
A five-day ceasefire was extended for 24 hours yesterday while delegations in Cairo from both sides tried to negotiate a deal to end weeks of fighting.
Israel has said repeatedly that it would not negotiate under fire and Mr Netanyahu has now ordered his negotiating team in Egypt to return home.
Egyptian mediators have been struggling to end the five-week-old Gaza conflict, where thousands of homes have been destroyed, Reuters reports.
The Palestinians want Egypt and Israel to lift their blockades of the economically-crippled Gaza Strip that predated the Israeli offensive launched on 8 July after a surge in cross-border rocket fire by Hamas.
The Palestinian Health Ministry put the Gaza death toll at 2016 and said most were civilians. Israel has said it killed hundreds of Gaza gunmen in the fighting. Sixty-four Israeli soldiers and three civilians in Israel have been killed.
Before the latest flareup, Azzam al-Ahmad, senior leader of President Mahmoud Abbas's Fatah movement, said there had been "no progress on any point" in the negotiations, in which Israel has said ensuring its security was its paramount concern.