Israeli forces has intensified its attacks in Jabalia in northern Gaza on Friday, after Israel had said its forces had cleared Jabalia months earlier in the Gaza war.
Residents said Israeli armour had thrust as far as the market at the heart of Jabalia, the largest of Gaza's eight historic refugee camps, and that bulldozers were demolishing homes and shops in the path of the advance.
Six people have been reported killed, while others wounded.
The Israeli bombardment in the north has coincided with the assault on Rafah at the southern edge of the Strip, sending hundreds of thousands of people fleeing from both ends of the territory at once.
At the World Court in The Hague, Israel asked judges to throw out a demand from South Africa for an emergency order to halt the assault on Rafah and withdraw Israeli troops from all of Gaza.