Gaza's Hamas-run health ministry said a second Israeli bombing raid in two days had killed and wounded "dozens" Wednesday at the territory's biggest refugee camp.
It said there were "dozens of martyrs and injured in a bombing by the occupation planes" at the Jabalia camp, a day after Israel acknowledged carrying out one devastating strike.
Images obtained by AFP showed dozens of rescuers pulling bodies and injured out of ruined buildings around another major hole left by Wednesday's shelling.
Rescuers said "whole families" were killed, but casualty details could not be immediately confirmed. Israel's military did not comment.
The Hamas health ministry says more than 50 people were killed in Tuesday's attack.
UN humanitarian chief Martin Griffiths denounced the Jabalia strike after a two-day visit to Israel and the occupied Palestinian territories.
"This is just the latest atrocity to befall the people of Gaza where the fighting has entered an even more terrifying phase, with increasingly dreadful humanitarian consequences," Griffiths said in a statement.
He said "the world seems unable, or unwilling, to act," adding "this cannot go on. We need a step change."
Griffiths said: "We need the warring parties to agree to pauses in the fighting" so that desperately needed relief aid can get into the Palestinian territory of 2.4 million people.
Israel said Tuesday's strike killed a senior Hamas commander based in Jabalia, Ibrahim Biari.
The daily air and ground raids by Israel has left more than 8,700 dead, including more than 6,000 women and children.
The Hamas military wing has said that seven of the hostages, including three with foreign passports, were killed in Tuesday's air attack.
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