The chief prosecutor of the International Criminal Court said Wednesday that she had opened a formal probe into alleged crimes in the occupied Palestinian territories, a move strongly opposed by Israel.

ICC prosecutor Fatou Bensouda has previously said there is a "reasonable basis" to believe crimes were committed by members of the Israeli forces, Israeli authorities, Hamas and Palestinian armed groups during the 2014 Gaza conflict.

"Today, I confirm the initiation by the office of the prosecutor of the International Criminal Court of an investigation respecting the situation in Palestine," Bensouda said in a statement.

Bensouda said there were "admissible potential cases" for the war crimes court, which was set up in 2002.

The prosecutor said the probe would be conducted "independently, impartially and objectively, without fear or favour". 

"In the end, our central concern must be for the victims of crimes, both Palestinian and Israeli, arising from the long cycle of violence and insecurity that has caused deep suffering and despair on all sides," she said.

Israel is not a member of the Hague-based ICC and has vehemently opposed any probe, but Palestine has been a state party to the court since 2015.

ICC judges paved the way for a war crimes investigation when they ruled a month ago that the court has jurisdiction over the situation due to Palestine's membership.

Bensouda said in December 2019 that she wanted a full investigation after a five-year preliminary probe, but asked the court to rule whether its reach extended to the Palestinian territories.

Israel’s Prime Minister Benjamin Netanyahu last month condemned the judges’ decision paving the way for a probe as "pure anti-Semitism”.

The US State Department said at the time it had "serious concerns” about the ICC ruling, adding that Israel should not be bound by the court as it was not a member.

Palestinian Prime Minister Mohammed Shtayyeh had praised February’s ICC ruling as "a victory for justice and humanity” while Hamas said it wanted to "bring the Zionist criminals of war before international courts and hold them responsible”.

The Israel-Palestinians probe will prove the first major test for incoming ICC Prosecutor Karim Khan, the British lawyer who was elected in February to replace Bensouda when her mandate ends in June.

Bensouda is under US sanctions for her decision to investigate alleged US war crimes in Afghanistan, but Washington has also strongly criticised the Palestinian probe.