Former President of Ireland Mary Robinson has accused both Israel and Hamas of committing war crimes since Hamas launched surprise attacks in Israel on Saturday morning.
Mary Robinson said Israel's response to the attacks was a collective punishment against the whole population of Gaza, many of whom do not support the actions of Hamas.
She accused Israel of carrying out "massive, indiscriminate bombing of Gaza" and said roughly 1,200 people had died in the last few days.
"I do not know how many injured, on top of that. There is the siege blocking food and fuel and electricity and water. That is a war crime," Robinson told RTÉ News.
Robinson said she did not accept the Israeli claims that the blockade was to ensure the safe return of Israeli citizens who had been taken hostage in Gaza.
"This is collective punishment against a whole population, many of whom don't support or don't like Hamas. It completely has to be dealt with on its own, cannot be in some way a bargaining chip or something. We also need much more protection of civilians."
However, she also said the Hamas attacks on Saturday morning were "very serious war crimes" and said the killings were not justified by what is happening to Palestinians under Israeli occupation.
Robinson spoke of the death of Irish-Israeli citizen Kim Damti, 22, who was killed by Hamas terrorists while attending a music festival in southern Israel on Saturday morning.
"These are very serious war crimes. They are not justified by what has been happening to the Palestinian people under occupation.
"Irish people are very aware of that. We must be very, very clear on that. We must not be ambivalent."
She called for protection for civilians to be increased and said there is a need to introduce "safe havens" if Israeli troops enter Gaza.
She added that humanitarian aid must be allowed into Gaza and said she was "very glad that the EU has spoken very clearly about this".
Robinson also said that Ireland has been a "very good voice" in acknowledging the suffering and occupation of Palestine in recent years.
She called for Israel to be held accountable for its actions in Gaza.
"Israel does not want to be accountable. The United States has not supported the International Criminal Court in relation to Israel. It does in relation to Ukraine, but not Israel and Western countries have been, to say the least, ambivalent and have not supported. Now is the time to support accountability.
"Ireland may be able to play a role here," she added.
Robinson, a former UN high commissioner for human rights, said she could sense tension during her last visit to Israel and Palestine in June but said she was shocked by how quickly things escalated.
She described the Israeli Government as a right-wing government that spoke openly about Israeli supremacy and potentially annexing the entire West Bank.
"We saw more settlements, more violence against Palestinians," Robinson said.
"The word apartheid came up in many discussions from Israeli human rights organizations, from former ambassadors of Israel, and even former military.
"On the West Bank and in Gaza, Israel was committing the crime of apartheid."
Meanwhile, Taoiseach Leo Varadkar has warned Israel that current solidarity could "fall apart" if it goes too far in Gaza.
Varadkar said many nations currently support Israel following Saturday's Hamas attacks but said any response from Israel must be proportionate.
"From Ireland's point of view, we are saying to Israel that 'yes you have a right to defend yourself, you are surrounded by enemies who want to end your existence, but any response must be proportionate'.
"There’s a lot of solidarity internationally for Israel at the moment – I believe that will fall apart if Israel goes too far in terms of its actions in Gaza."
In a separate interview, Varadkar said Israel was breaching international law by "targeting civilians" and cutting off electricity and water.
"They do have a right to defend themselves, but they don't have the right to breach international humanitarian law. And I'm really concerned about what I'm seeing happening in Gaza at the moment," Varadkar told RTÉ's Primetime.
"To me, it amounts to collective punishment, cutting off power, cutting off fuel supplies and water supplies. That's not the way a respectable democratic state should conduct itself.
"I believe by targeting civilians and by cutting off civilian infrastructure that is a breach of international humanitarian law. And I think it's very important for us as Ireland to make sure that that voice is brought to the table at European Union level."
Tánaiste Micheál Martin said Ireland will be "very clear" that EU aid must continue to reach Gaza in the coming months.
"The move by Israel to engage with Hamas and to deal with Hamas, that obviously will have consequences on the humanitarian side, and our contribution later will be very clear that humanitarian aid from the European Union has to continue to reach Palestinians in the area of education, in the area of health, and in the area of food provision," Martin said.