Israel launched at least 10 air strikes in response to rocket and mortar fire from Gaza. One hit near a mosque and killed a 10-year-old boy, Palestinian officials said. In Israel, two people were hurt by rocket fire, police said.
It is not clear if the renewed fighting will derail the Cairo talks, which are aimed at reaching a sustainable truce, or if Egyptian mediators can find a way to prevent further escalation.
Hamas officials said that even though it refused to extend the three-day ceasefire, it was willing to continue negotiations.
An Israeli government official said Israel would not conduct negotiations under fire and would protect its citizens by all means.
The Israeli delegation left Cairo yesterday morning, and it was not clear if it would return. Minutes after the temporary truce expired at 8am local time, Gaza militants began firing rockets. By midday, 33 rockets had been fired. Israel responded with what the military said were strikes "across Gaza".
Police in Gaza said most of the strikes hit empty fields, but one struck the grounds of the Nour al-Mohammadi Mosque in the Gaza City. Gaza health official Ashraf al-Kidra said a 10-year-old boy was killed and five boys were wounded, one of them critically.