GAZA CITY, Gaza Strip (AP) -- Nearly a month into Israel's fierce assault on Hamas in Gaza, Palestinian President Mahmoud Abbas is facing mounting domestic pressure to seek war crimes charges against Israel at the International Criminal Court.
He has hesitated in the past because such a move would instantly put the Palestinians on a risky collision course with Israel. But with about 1,400 Palestinians killed in Gaza, according to health officials, Abbas has signaled he might move ahead -- cautiously.
Palestinian officials said Thursday that Abbas asked all Palestinian political factions, including Hamas and the smaller group Islamic Jihad, to give their written consent to such a move. Different PLO factions signed up in a meeting in the West Bank earlier this week, while Abbas is still waiting for a response from Hamas and Islamic Jihad, they said.
In trying to make a case against Israel, Abbas could also expose Hamas, a bitter rival turned potential political partner, to war crimes prosecution because it has fired thousands of rockets from Gaza at Israeli communities over the years.
"This option is a double-edged sword," Abbas' Fatah movement wrote on its official Facebook page Thursday, saying he would only move ahead once he has the approval of Hamas.
In Geneva, U.N. High Commissioner for Human Rights Navi Pillay on Thursday accused both Israel and Hamas militants of violating the rules of war.
She said Hamas is violating international humanitarian law by "locating rockets within schools and hospitals, or even launching these rockets from densely populated areas." But she added that this does not absolve Israel from disregarding the same law.
Pillay said the Israeli government has defied international law in Gaza by attacking civilian areas such as schools, hospitals, homes and U.N. facilities.
"None of this appears to me to be accidental," Pillay said of Israel. "They appear to be defying -- deliberate defiance of -- obligations that international law imposes on Israel."
Pillay also took aim at the U.S., Israel's main ally, for providing financial support for Israel's "Iron Dome" anti-rocket defense system. "No such protection has been provided to Gazans against the shelling," she said.
Israeli Foreign Ministry spokesman Yigal Palmor declined comment on Pillay's allegations and on the Palestinian deliberations concerning the ICC.
Israeli officials have said Israel is acting in self-defense by targeting Hamas' military arsenal and rocket-launching sites. They have accused Hamas of using Gaza civilians as human shields.
At the United Nations, Israel's Ambassador Ron Prosor responded to criticism of his country, saying: "I think the international community should be very vocal in standing with Israel fighting terrorism today because if not, you will see it on your doorstep tomorrow."
Riyad Mansour, the Palestinian U.N. ambassador, told reporters "There is no safe place in the Gaza Strip."
Hamas has portrayed its rocket fire on Israel as legitimate resistance to Israeli occupation of Palestinian territories.
The current round of fighting marks the third Israel-Hamas war in just over five years. In each round, mutual war crimes allegations have been raised, but neither side pursued them further.
After the first war in 2009, Abbas -- in an apparent effort not to antagonize the U.S. -- helped freeze a U.N. report that called on Israel and Hamas to prosecute any war crimes or face scrutiny by the ICC.
Now, Abbas has more tools at his disposal.
In November 2012, the U.N. General Assembly recognized Palestine in the West Bank, Gaza and east Jerusalem -- lands Israel captured in 1967 -- as a non-member observer state.
This state remains largely theoretical since Israel retains control of the West Bank and east Jerusalem and of Gaza's border points. However, the U.N. vote improved Palestinian chances to seek admission to the International Criminal Court since the tribunal only has jurisdiction over crimes committed in the territory of a state.
The statehood recognition paved the way for the Palestinians to seek membership in dozens of U.N. agencies and international conventions.
Abbas signed a first batch after nine months of U.S-brokered negotiations with Israel ran aground in April, and Palestinian officials said more membership requests would follow, despite opposition by Israel and the U.S.
Gaining membership to the ICC has been considered the Palestinian "doomsday weapon" because it would likely invite major Israeli retaliation.
But widespread anger in the West Bank over the rising casualties in Gaza has increased pressure on Abbas to act.
"People feel that this tool should be used to stop the Israeli crimes," said former Palestinian government spokesman Ghassan Khatib.