Palestinian Authority President Mahmoud Abbas has declared that Israel is committing "genocide" in Gaza as the Palestinian civilian death toll from "Operation Protective Edge" continues to rise.

"It's genocide - the killing of entire families is genocide by Israel against Palestinian people," he said at a crisis meeting of the Palestinian leadership in the West Bank administrative capital of Ramallah.

Gaza's health ministry has said that the death toll now stands at 81 Palestinians dead with 22 children killed since Israel's campaign of air strikes began.

Israel claims that it is striking against Hamas militants and high-value targets such as rocket stockpiles and military training grounds.

"What's happening now is a war against the Palestinian people as a whole and not against the (militant) factions," said Abbas.

"We know that Israel is not defending itself, it is defending settlements, its main project.

"We are moving in several ways to stop the Israeli aggression and spilling of Palestinian blood, including talking to Egyptian President (Abdel Fattah) al-Sisi and UN secretary general Ban Ki-moon."

Israel has struck over 550 targets in their operation they claim is in retaliation for rockets fired at major Israeli cities such as Jerusalem and Tel Aviv.

The leader of the Anti-Defamation League (ADL) Abe Foxman condemned Abbas's comments.

"This is unacceptable language and accusations coming from the leader of the Palestinian Authority," Foxman said.

"We are used to the outrageous criticisms of Israel coming from Palestinians, but President Abbas has reached a new low in calling Israel's self-defence action, after hundreds of rockets have been launched at Israeli civilians, a 'genocide'."

Gaza-based militants, from both Hamas and the Islamic Jihad, have fired 165 rockets at Israeli cities as far as Hadera, 116km (72 miles) north of the enclave. No casualties have been caused by the missiles.

Egypt has urged both sides to halt the escalating conflict but suggested that there was little hope for an Egyptian-mediated truce.

"There is no mediation, in the common sense of the word," said Egyptian foreign ministry spokesman Badr Abdelatty.

"Egyptian diplomatic efforts are aimed at immediately stopping Israeli aggression and ending all mutual violence. (Egyptian) contacts have not yet achieved a result."