Vital aid supplies to the Gaza Strip have been halted after a series of rocket attacks over the border into Israel.
All frontier crossings were closed, stranding food and fuel on the Israeli side.
Three quarters of a million people in Gaza depend on international handouts to survive. What food exists there is already rationed, and the UN warned supplies may start running out this weekend.
Israel sealed off Gaza following a wave of rocket attacks. The town of Ashkelon was hit by long-range Grad missiles, and more rockets were fired at other targets in southern Israel, but no-one was hurt.
Eleven days of sporadic rocket fire has prompted some Israelis to demand the five-month old truce with Hamas be scrapped. They want the army to act against the rulers of Gaza, targetting the group’s leaders.
At least two Palestinians were wounded in retaliatory Israeli air strikes. The military said there was no immediate chance of the Gaza border crossings being re-opened to allow aid back in.