NEW YORK - As the Israeli occupation of the West Bank and Gaza entered its 50th year, Human Rights Watch, a prominent international watchdog body, Sunday called on the International Criminal Court (ICC) prosecutor to open a formal investigation into serious international crimes committed against Palestinians.

 Given strong evidence that serious crimes have been committed in Palestine since 2014, including new population transfers into occupied territories, the ICC prosecutor, Fatou Bensouda, should undertake a formal probe consistent with the ICC’s Rome Statute, Human Rights Watch said. An ICC investigation is needed given the grave nature of many of the violations and the pervasive climate of impunity for those crimes.

 “After nearly a half century of impunity, it’s time that those responsible for some of the gravest crimes, whether against Palestinians or Israelis, pay the price,” Sarah Leah Whitson, Middle East director, said in a statement. “The ICC prosecutor should move forward and investigate the crimes by all parties so that the victims can obtain a measure of justice that has long eluded them.”

 Human Rights Watch issued its statement on the 49th anniversary of the start of the June 1967 (or Six Day) War that resulted in the occupation of the Palestinian territories.

 The ICC treaty officially went into effect for Palestine on April 1, 2015, giving the court jurisdiction over serious crimes in violation of international law, including war crimes and crimes against humanity committed on or from Palestinian territory. On January 1, 2015, the Palestinian government gave the court a mandate back to June 13, 2014, to cover the 2014 conflict in Gaza.

 Human Rights Watch, the UN and local and international human rights organizations have already said Israel’s latest war on the besieged Gaza Strip amounts to apparent war crimes.

Israel launched its 50-day onslaught on Gaza in early July 2014. The military aggression, which ended on August 26, killed nearly 2,200 Palestinians, including over 570 children.Gaza has been under an Israeli siege since June 2007. The blockade has caused a decline in the standards of living as well as unprecedented levels of unemployment and unrelenting poverty.

Last June, Palestinian Foreign Minister Riad al-Maliki submitted information to Bensouda’s office to help her better undertake the inquiry into the Israeli crimes. The ICC prosecutor was provided with further information on August 3 and October 30 that year.

Palestinian NGOs, including Al Mezan Center for Human Rights, Al-Haq, Aldameer, and the Palestinian Center for Human Rights, have also submitted several pieces of information to the ICC in order to be taken into consideration.

On Thursday, the ICC’s prosecutor said Israel was holding discussions with the International Criminal Court over its inquiry into possible war crimes in the 2014 Gaza war.

“Israel has agreed to engage with my office and we are exchanging information,” Bensouda said during a visit to the UN in Geneva.

Until now, Israel has publicly declined all cooperation with the ICC on investigations related to its conflict with the Palestinians.

Among other Israeli crimes against Palestinians are the construction of illegal settlements across the occupied West Bank in defiance of international calls for a halt to the process.

According to the Israeli Central Bureau of Statistics, the number of Israeli settlers in the West Bank, excluding East al-Quds (Jerusalem), increased by about 14,000 in 2014.

A total of 1,177 Palestinians were made homeless as result Israeli demolitions of Palestinian homes and other buildings in the West Bank in 2014, and a further 757 Palestinians were displaced last year.

Israel started construction work on 1,913 new housing units in illegal settlements across the West Bank, not including East al-Quds, in 2015, and finished construction of 2,033 housing units there, according to Israel’s Central Bureau of Statistics.

More than half a million Israelis live in over 230 illegal settlements built since the 1967 Israeli occupation of Palestinian territories in the West Bank and East al-Quds (Jerusalem).