Criminal Court: War crimes committed by Israel against the Palestinians.

Prosecutors at the International Criminal Court opened a preliminary examination on Friday into possible war crimes committed in the Palestinian territories, the first formal step that could lead to charges against Israelis.

An announcement of the inquiry by the court's chief prosecutor, Fatou Bensouda, came two weeks after the Palestinians, over the strong objections of Israel and the United States, signed the Rome Statute, the treaty that created the court in The Hague.

Ms. Bensouda's announcement, which had been expected, did not necessarily indicate that she would pursue charges in her investigations of actions by Israel that the Palestinians assert to be war crimes.

Her preliminary examination, which could take months or even years, could theoretically also lead to charges against Palestinians for violence against Israelis in the nearly five decades of hostilities between the two sides.

Even so, the step raised the level of antipathy between Israel and the Palestinians, whose relations were already under severe strain over the long-paralyzed diplomacy aimed at a two-state solution to their protracted conflict.

The Palestinians recognized the court's jurisdiction retroactively, which means a preliminary investigation would cover a period that includes the 50-day war last summer between Israel and Palestinian militants in Gaza.

Foreign Minister Avigdor Lieberman of Israel denounced Ms. Bensouda's announcement, made as many Israelis were preparing for the Jewish Sabbath, as "outrageous," according to a report on I24, an Israeli news website.

President Mahmoud Abbas of the Palestinian Authority had threatened for more than two years to use Palestine's status as a nonmember observer state at the United Nations, attained in November 2012, to join the International Criminal Court, which investigates and prosecutes war crimes and other atrocities.

Palestinian officials have described joining the court as part of a shift in strategy by Mr. Abbas to pressure Israel - a strategy that also includes seeking a deadline for Israeli withdrawal from lands occupied after the 1967 war.

In her announcement, posted on the court's website, Ms. Bensouda said that she was undertaking the inquiry at the Palestinians' request, and that it was a required procedure. "The office will conduct its analysis in full independence and impartiality," she said.

The Israeli government froze Palestinian tax revenue after Mr. Abbas began the formal process of joining the court at the beginning of January.

The United States, which has called Palestinian membership in the court a counterproductive step toward a peace agreement, has warned that American aid to the Palestinian Authority could also be imperiled