A UN commission on Tuesday concluded that Israel is committing genocide against Palestinians in the Gaza Strip, urging Israel to immediately cease its atrocities in the Palestinian enclave.

The Israeli authorities and security forces have committed four of the five acts of genocide, including killing, causing serious physical and mental harm, deliberately destroying the living conditions, and implementing measures aimed at preventing fertility, the UN Independent International Commission of Inquiry on the Occupied Palestinian Territory, including East Jerusalem, and Israel said in a report.

The top Israeli authorities bear responsibility for the atrocities in the Gaza Strip by planning a genocidal campaign for nearly two years with the clear intention of destroying the Palestinian community in the area, said Navi Pillay, chair of the commission.

Pillay said that Israel had continued its strategy of eliminating Palestinians in Gaza, blatantly ignoring warnings from the international community and the mandate of the International Court of Justice for interim measures.

"The Commission finds that the Israeli authorities had no intention to change their course of actions," she said, urging the Israeli government to comply immediately with its international legal obligations, including halting the genocide, ending the hunger policy and lifting the blockade on the Gaza Strip to allow the entry of humanitarian aid.

It also called on its member states to stop transferring arms and other equipment to be used for the Israeli crimes in Gaza, and take action against individuals or corporations that are involved in the genocide.

On the same day, the Israeli foreign ministry rejected the report, calling it "fake" and accusing the authors of being "Hamas proxies."

"The report relies entirely on Hamas falsehoods, laundered and repeated by others," the ministry said.

Israeli Prime Minister Benjamin Netanyahu said on Tuesday that Israel has launched an "intense operation" in Gaza City.

Video footage on social media showed heavy bombardment by aircraft and artillery, with flares and fires rising above buildings.

Local health authorities in Gaza reported that at least 37 people were killed and dozens went missing in Gaza City, with four more killed elsewhere in the enclave.

Israel's military has ramped up forces over the past weeks ahead of what Netanyahu and other officials described as a major ground and air offensive to "conquer" Gaza City, the enclave's main urban center.