At least 17 people were killed and 200 people wounded in an Israeli air strike on a market near Gaza City on Wednesday, medics said.
Emergency services spokesman Ashraf al-Qudra said the strike hit a busy market in the battered Shejaiya neighbourhood, which lies between Gaza City and the border with Israel.
The strike came shortly after the Israeli army said it was observing a humanitarian lull that would be in force for four hours from 1200 GMT.
But it said the lull would not apply in areas where troops were "currently operating", in a move denounced as a publicity stunt by Hamas.
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Thick black smoke billowed over the site as at least five ambulances raced to the scene where bodies lay strewn on the ground, an AFP correspondent said.
A bloodied, limp lifeless body lay in a pool of petrol and mud, his head crushed.
A nearby building belted out smoke, still on fire, and the street was strewn with debris.
Medics worked frantically to recover the wounded and dead, loading at least five bodies onto stretchers then driving them off in ambulances.
Among those lying on the ground was a man wearing a flak jacket marked "Press", although it was not immediately clear whether he was dead or wounded.