Media building used by Reuters and a number of pan-Arab news agencies has been hit in the centre of #Gaza City
UN relief agency spokesman says #Gaza headquarters was hit by at least three shells containing white phosphorus.
Hospital in Tal El-Hawa in central #Gaza bombed with 500 people inside.
At least 1,054 people have been killed in #Gaza since war began, Palestinian medical sources say. More than 4,860 people also injured.
Israeli navy turns back #Gaza aid boat which sailed from Cyprus carrying doctors, journalists and emergency medical supplies.
John Ging, the head of UN operations in Gaza told al-Jazeera television: "This is going to burn down the entire warehouse ... thousands and thousands of tonnes of food, medical supplies and other emergency assistance is there."
He said the phosphorus fires were hard to extinguish "because if you put water on it, it will just generate toxic fumes and do nothing to stop the burning". Phosphorous munitions are banned under international law as a weapon but permitted if used to create a smokescreen.