Tánaiste Micheál Martin has condemned Israel's military operation in Rafah, which as of Monday evening has reportedly killed more than 70 people.

"I'm in no doubt, and we are in no doubt, that the continued bombardment on Rafah will constitute a war crime and will certainly, in my view, gravely violate international humanitarian law," the Tánaiste told reporters on Monday, according to RTÉ News.

"We are looking now at what is the largest refugee camp in the world in terms of one and a half million people in Rafah; they cannot be displaced safely.

"To bomb and to mount a military operation in such confined area with so many people is absolutely inhumane, unacceptable, and the international community must do everything it can to put the pressure on Israel not proceed with this invasion.

"It is very, very serious. It will create catastrophic conditions on top of what are already dire situations for families and civilians in Gaza."

The Tánaiste's comments on Monday come two days after he responded to Israeli Prime Minister Benjamin Netanyahu's announcement that there would be expanded military operations and Rafah and that he had ordered the evacuation of the area.

The military operation and orders for evacuation "pose a grave threat to the estimated 1.5 million Palestinians sheltering in the area, and must be condemned," the Tánaiste said in a statement on Saturday.

"I have repeatedly stressed that international humanitarian law imposes a clear obligation on all parties, to all conflicts, to ensure the protection of civilians.

"It is absolutely clear that a military operation in Rafah, which has effectively now become one of the largest and most overcrowded refugee camps in the world, would entail grave violations of international humanitarian law.

"It is also absolutely clear that ordering the evacuation of 1.5 million people, who have nowhere safe to go, risks mass forced displacement.

"This can not be allowed to happen. All countries, including all EU Member States, must demand an immediate humanitarian ceasefire.

"There can be no further equivocation."

The Tánaiste said Hamas must release all hostages immediately and unconditionally and also called for the provision of "full, safe and unhindered humanitarian access."

He continued: "Wholly inadequate humanitarian access over the last 4 months means that the UN estimates that 90% of the population face acute food insecurity, with a serious risk of famine developing. This is unconscionable.

"Freezing or withdrawing funding to UNRWA further exacerbates these risks - States which have done so must urgently rescind this decision and resume funding."

The Tánaiste said he will discuss with UNRWA Commissioner General Lazzarini what further support Ireland can provide to UNRWA during Lazzarini's visit to Dublin this week.

At the time of publication on Monday, Reuters was reporting that 74 Palestinians had been killed in the Israeli assault in Rafah and that Israel had freed two hostages from Hamas.