STORY: This video released on Tuesday (May 7) is believed to be the moment Israeli tanks pushed into a park near the Gaza side of the Rafah border crossing.
Soldiers were seen raising an Israeli flag.
Reuters was unable to independently verify the date of the footage.
It came after a night of air strikes on the Palestinian enclave, amid international concern over the plight of civilians crammed into Rafah.
And as mediators struggled to secure a ceasefire agreement between Israel and Hamas.
The Palestinian militant group said late on Monday (May 6) it had agreed to a ceasefire proposal but Israel said the terms did not meet its demands.
A Gaza border authority spokesperson told Reuters the Rafah crossing, a vital route for aid into the enclave, is now closed.
Aid trucks were seen stuck at the Egypt side of the Rafah crossing.
And in a field hospital in Rafah, Dr. Marwan al-Hams said the closure of the crossing will cause further crisis for the enclave's healthcare.
"The closure of the Rafah crossing means the death of thousands of patients, thousands of injured will be martyred. Nutritional resources, medical resources and humanitarian aid won't enter Gaza Strip, which means more diseases, more patients needing treatment that isn't available, more patients with chronic diseases, new diseases we won't find medication for and therefore, the numbers of patients will pile up."
On Tuesday morning, people searched for bodies under rubble of wrecked buildings in Rafah.
More than one million people have sought refuge here, living in tented camps and makeshift shelters.
Many are trying to leave, heeding Israeli orders for them to evacuate.
But with large areas of the coastal enclave already laid to waste, they say they have nowhere safe to go.
The Israeli military said a limited operation in Rafah was meant to kill fighters and dismantle infrastructure used by Hamas.
Israel says the vast majority of people had been evacuated from the area of military operations and it has told them to go to what it calls an "expanded humanitarian zone" around 12 miles away.
Egypt said the Israeli operation in Rafah threatened the ceasefire efforts.
And the European Union's foreign policy chief, Josep Borrell said the assault would be deadly.
"I am afraid that this is going to cause again a lot of casualties, civilian casualties, whatever they say.// There is no safe zones in Gaza."
As ceasefire talks stumbled, mediator Qatar said its delegation would head to Cairo on Tuesday to resume indirect ceasefire negotiations between Israel and Hamas.
A Palestinian official close to mediation efforts told Reuters a Hamas delegation may arrive in Cairo later on Tuesday or on Wednesday.
A senior Israeli official also said on Tuesday that a team of mid-ranking Israeli officials will go to Egypt to assess whether Hamas can be persuaded to shift on its latest ceasefire offer.
The official reiterated that the proposal as it stands was unacceptable to Israel.
