Israeli Prime Minister Benjamin Netanyahu says the strike which killed scores of displaced Palestinians in Rafah was a “tragic mishap”.
Speaking in the Israeli parliament, Mr Netanyahu said it was vital that Israel took “every precaution possible” to protect civilians caught up in the fighting in Gaza.
He told MPs that an investigation into the incident was under way, but insisted that the Israel Defense Forces (IDF) had used their “best efforts not to harm those uninvolved” in the conflict.
The intervention comes amid increasing condemnation of the strike which killed at least 45 people, according to the Hamas-run health ministry.
“In Rafah we already evacuated about one million non-combatant residents and despite our outmost effort not to harm non-combatants, something unfortunately went tragically wrong,” Mr Netanyahu said.
“We are investigating the incident and will reach conclusions because this is our policy.”
International organisations have lined up to condemn the strike, with the EU insisting that Israel respect a ruling by the International Court of Justice last week to halt strikes on Rafah.
The bloc’s top diplomat, Josep Borrell, called Sunday’s strike “horrifying”.
Meanwhile the UN’s human rights chief, Volker Turk, said the attack suggested that there had been “no apparent change in the methods and means of warfare used by Israel that have already led to so many civilian deaths”.
Israel launched the Rafah attack just hours after Hamas launched its first missile attack on Tel Aviv in several months.
IDF officials insisted that the attack had killed two senior Hamas commanders, and that it was investigating the deaths of civilians in the area.
But the Palestinian Red Crescent said Sunday’s air strike targeted tents for displaced people near a UN facility in Tal al-Sultan, about 2km (1.2 miles) north-west of the centre of Rafah.
Videos from the scene in the Tal al-Sultan area on Sunday night showed a large explosion and intense fires burning.
Graphic footage showed a number of structures ablaze next to a banner saying “Kuwaiti Peace Camp ‘1’”, as well as first responders and bystanders carrying several bodies.
