The Egyptian foreign ministry has condemned Israel's deadly overnight air strikes on Gaza on Tuesday, calling them a "flagrant violation" of the ceasefire that took effect on January 19.

The strikes constitute a "dangerous escalation which threatens to bring serious consequences for the stability of the region", said the statement from Egypt, which brokered the Gaza ceasefire alongside Qatar and the United States.

It called on the international community to "act immediately to halt the Israeli aggression against Gaza in order to prevent the region entering a new spiral of violence and counter-violence".

Israel's overnight strikes, which the health ministry in Hamas-run Gaza said killed more than 400 people, were by far the biggest since the ceasefire. Hamas has not responded militarily so far.

Jordan, which, like Egypt, neighbours Israel, also condemned the strikes.

"We have been following since last night Israel's aggressive and barbaric bombing of the Gaza Strip," government spokesman Mohammed Momani said, underlining "the need to stop this aggression".

US President Donald Trump has floated a proposal to move Gaza's population out of the war-battered territory, suggesting that Egypt or Jordan could take them in.

Both countries, along with other Arab allies, governments around the world and the Palestinians themselves, have flatly rejected the notion.

Arab nations have since come up with an alternative plan for rebuilding the Gaza without relocating Palestinians.