More than 1.5 million people occupy an area 147 square miles.
Christopher Gunness is the spokesman for the UN agency assisting Palestinian refugees-UNRWA.
He tells UN radio from Jerusalem that the situation for civilians is getting worse by the hour.
"I'm pleased to say that we were able at UNRWA to get 32 trucks in to Gaza today of food and medicine. The medicine is being taken straight to hospitals which are overwhelmed to breaking point, and the food will go to our warehouses. We hope to have news about resuming food distributions, but I can say nothing really about that. So things are getting bad-but there was some hope in the form of some aid getting through today."
Gunness says "the aerial bombardment is intense", making it "very dangerous" to try and deliver humanitarian aid to Gaza.
This is Donn Bobb reporting for United Nations Radio.
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