The U.S. received information from the Israelis overnight that they believe shrapnel or something else from the strike ignited a fuel tank 100 meters away, which engulfed a tent, creating a massive fire, according to a U.S. official.

The U.S. does not have information to confirm or dispute that information. The U.S. is in the process of understanding what has happened, waiting for Israel to conduct its own investigation and determining what action to take next, according to the official.

The U.S. maintains that while they’ve warned about a major ground offensive in Rafah, that’s not what’s happening, according to the official.

-ABC News' Selina Wang

Commenting on the Rafah strike that killed 50 people, Hamas released a statement saying Israel’s attack on Rafah is like "the announcement of Netanyahu’s government’s defiance of international justice decisions," referring to the International Court of Justice’s decision last week ordering Israel to stop its operation in Rafah.

"The massacre committed in the areas where its considered safe area," Hamas leader Osama Hamdan said. "The timing of these murders during the last two days is like the announcement of Netanyahu's government's defiance of international justice decisions."

Israeli Prime Minister Benjamin Netanyahu called the strike on Rafah which killed at least 50 Palestinians Sunday, a “tragic mishap,” in a speech to Israel’s parliament, the Knesset, Monday.

"We are fighting with force in the north of the Gaza Strip, in its center, its south and in Rafah. In Rafah we have already evacuated about a million uninvolved residents and despite our best efforts not to harm the un-involved, unfortunately a tragic mishap happened last night. We are investigating the case and will draw the conclusions because this is our policy," Netanyahu said.

-ABC News' Ellie Kaufman

At least 50 people have been confirmed dead in Israel's strike on Rafah, with a number of victims are still under the rubble, the Gaza Health Ministry said in a statement Monday. Ambulance and civil defense crews cannot reach them the victims, the statement noted.

Since Oct. 7, 36,050 people have been killed in Gaza and 81,026 others have been injured.

"Never before in history has such a large number of mass killing tools been amassed and employed together in front of the world as is happening now in Gaza, where the population is deprived of water, food, medicine, electricity, and fuel, crushing the infrastructure, destroying all institutions, disrupting sanitation, spreading epidemics, crushing the health system, implementing the siege, closing crossings, and preventing the entry of medical supplies and delegations," the Gaza Health Ministry said.

-ABC News' Will Gretsky

Although President Joe Biden on Friday outlined a multi-phase cease-fire proposal he said came from Israel, the Israeli Prime Minister’s Office said in a statement Saturday that "Israel's conditions for ending the war have not changed: the destruction of Hamas's military and governing capabilities, the freeing of all hostages and ensuring that Gaza no longer poses a threat to Israel."

"Under the proposal, Israel will continue to insist these conditions are met before a permanent cease-fire is put in place," the statement said. "The notion that Israel will agree to a permanent cease-fire before these conditions are fulfilled is a non-starter."

Biden said Friday that Israelis should feel comfortable with a cease-fire because Hamas’s capabilities have deteriorated and can no longer repeat the Oct. 7 terrorist attacks.

Hamas in a statement reiterated its requirements for a deal. Hamas said it "affirms its position of readiness to deal positively and constructively with any proposal based on a permanent cease-fire, complete withdrawal from the Gaza Strip, reconstruction, the return of the displaced to all their places of residence, and the completion of a serious prisoner exchange deal."