Israeli attacks on central Gaza killed at least 62 people including women and children, according to medical sources in the Palestinian territory on Wednesday.
The Israel Defense Forces (IDF) said they were investigating.
Earlier, the IDF said it had begun targeted operations in al-Bureij in central Gaza and areas in the east of Deir al-Balah on Tuesday.
The IDF said it had carried out airstrikes targeting military compounds and weapons depots of Palestinian militant group Hamas, as well as underground infrastructure belonging to the group. "Several Hamas terrorists were eliminated in the attacks," the IDF said.
Israeli soldiers had previously deployed in al-Bureij at the beginning of the year, but later withdrew from the area. However, Hamas is still present in the densely populated area, the IDF said.
Residents of the two neighbouring refugee camps of al-Bureij and al-Maghazi told dpa on Wednesday that there had been uninterrupted attacks in the area throughout the night and that thousands of people had fled to the Nuseirat refugee camp nearby.
The IDF also continued operations in Rafah in the south of the coastal region, saying armed men who posed a threat to Israeli soldiers were killed.
Mediators to meet to advance ceasefire efforts
Sources on Wednesday said that officials from the United States, Egypt and Qatar were due to meet in Doha to advance efforts to reach a ceasefire and hostage deal between Israel and Hamas.
CIA Director William Burns and White House Middle East Coordinator Brett McGurk travelled to the region again to promote the long-elusive deal, media reports said.
They would hold talks in Qatar and Egypt and possibly also visit Israel, the Times of Israel said.
Chief of the Egyptian intelligence service, Abbas Kamel, left for Doha on Wednesday for talks with Burns and Qatari Prime Minister and Foreign Minister Mohammed bin Abdulrahman Al Thani, sources at Cairo airport said.
The talks come as ceasefire efforts have picked up fresh momentum after US President Joe Biden last week laid out a plan to end the conflict in Gaza in three phases, starting with a complete and unrestricted ceasefire of six weeks.
On Tuesday, Qatar said neither the Israeli government nor Hamas had yet made a clear statement on the latest proposal.
On Tuesday evening, a Hamas representative said the militants are sticking to their demands and will only agree to a deal to end the war if it includes a permanent ceasefire.
In addition, the Israeli military would have to withdraw completely from the Gaza Strip, the representative said at a press conference in Beirut, adding that if the Israeli side does not agree to these points, no agreement can be reached.
Hamas is waiting for the Israelis' response. Hamas representatives have made similar demands several times in the past.
For months, Qatar, the US and Egypt have been indirectly mediating between Israel and Hamas in order to achieve a ceasefire and an exchange of Israeli hostages for Palestinian prisoners.
The war was triggered by the unprecedented massacre carried out by militants from Hamas and other extremist Palestinian organizations in Israel near the border with the Gaza Strip on October 7.
The militants killed more than 1,200 people and abducted more than 250 hostages to the Gaza Strip.
Israel responded with massive airstrikes and a ground offensive. According to the Hamas-controlled health authority, 36,550 people have been killed so far and a further 82,959 have been injured.
These figures, which do not differentiate between fighters and civilians, cannot be independently verified at present.