The number of people killed has reached 500 following the alleged air strike on a hospital – according to the Gaza health ministry spokesman.
Meanwhile, Israeli army spokesperson says the cause of the incident not known and the army are looking into the details.
The BBC is working to verify details of the alleged incident.
Meanwhile, at least six people have been killed when a school was hit during air strikes in the al-Maghazi refugee camp in the Gaza Strip, the United Nations says.
Dozens of others were injured, and it’s thought the numbers will increase, according to the statement from the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA).
“This is outrageous, and it again shows a flagrant disregard for the lives of civilians,” the statement adds. “No place is safe in Gaza anymore, not even UNRWA facilities.”
UNRWA says the hit took place during Israeli bombardment of the Gaza Strip.
It adds: “At least 4,000 people have taken refuge in this UNRWA school turned shelter. They had and still have nowhere else to go.”
Earlier the Israeli military insisted it was not targeting civilians, adding: “When we see a Hamas target, we will go after it”.
At least 600,000 people have fled the northern Gaza Strip for the south after Israeli military warnings.
Israel has blocked supplies of food, water, fuel, and electricity since the deadly Hamas attacks on 7 October – but denies there is a humanitarian crisis.
US President Joe Biden will visit Israel on Wednesday to hear about its plans for a ground attack in Gaza.
Husam Zomlot, the Palestinian ambassador to the UK, says the situation in Gaza is “almost like living in an unimaginable horror movie”.
Zomlot says people in Gaza have to make “horrific” choices over whether they should stay in their homes, how they ration water and food, and if they should continue vital medical care like cancer treatment or dialysis.
“It’s really unimaginable what has happened,” he tells BBC News.