An Egyptian border guard was killed in a shooting in the Rafah border area with Gaza, Egypt’s military spokesman said in a statement on Monday.

"The Egyptian armed forces, through the competent authorities, are investigating a shooting incident in the Rafah border area which led to the martyrdom of one of the security personnel on duty," the statement said.

The Israeli military had earlier reported an exchange of fire on the Egyptian border and said it was discussing the incident with Egypt.

“A few hours ago (Monday), a shooting incident occurred on the Egyptian border. The incident is under review and discussions are being held with the Egyptians,” the IDF said.

Initial investigations into an incident that killed an Egyptian border guard indicate the incident occurred while there was an exchange of fire between Israeli forces and "the Palestinian resistance," an Egyptian security source told Egypt’s state-affiliated Al Qahera News TV on Monday.

In October 2023, weeks after the war started, Israel said one of its military tanks mistakenly fired at an Egyptian position near the border with Gaza. Egypt said at the time that several army personnel were slightly injured.

Tensions between Egypt and Israel have escalated after Israeli forces earlier this month seized control of the Rafah border crossing, a key entry point for humanitarian aid. Egypt said it would not reopen its side of the crossing unless it is operated by Palestinians and accused Israel of preventing aid deliveries.

-ABC News' Ayat Al-Tawy

The images that have emerged after the Israeli strike on Rafah are a "testament to how Rafah has turned into hell on earth," Philippe Lazzarini, commissioner general of the United Nations Relief and Works Agency for Palestine Refugees in the Near East, said in a post on X.

"Children and women living in tented plastic makeshift shelters are among the killed. Many were injured. Others were reportedly burnt to death. The images from last night are testament to how Rafah has turned into hell on earth," Lazzarini said went on.

Some UNRWA staff are unaccounted for and it’s very hard to establish contact with UNRWA teams in Rafah, Lazzarini said, adding that the UNRWA is doing its best to bring aid to people in need in Gaza.

"UNRWA is doing everything possible not to interrupt the delivery of humanitarian assistance. But with every day passing, providing assistance & protection becomes nearly impossible," he said.

-ABC News' Ellie Kaufman

The "devastating images" coming out of Rafah are "heartbreaking," a White House National Security Council spokesperson said in a statement Monday, adding that even though Israel "has a right to go after" Hamas, the country also has to protect civilians.

"Israel has a right to go after Hamas, and we understand this strike killed two senior Hamas terrorists who are responsible for attacks against Israeli civilians," the spokesperson said. "But as we’ve been clear, Israel must take every precaution possible to protect civilians."

The spokesperson also said that the U.S. is engaging with the Israeli authorities to figure out "what happened" in addition to the IDF investigation.

-ABC News' Michelle Stoddart

French President Emmanuel Macron condemned Israel's attack on Rafah that left at least 45 people dead, saying he was “outraged" and called for “respect for international law” and an "immediate cease-fire."

“Outraged by the Israeli strikes which caused numerous victims among the displaced in Rafah. These operations must stop. There are no safe areas in Rafah for Palestinian civilians. I call for full respect for international law and an immediate ceasefire,” Macron said in a post on X.

The Israel Defense Forces claimed it took several measures to protect civilians. The strike is now under investigation.

"The General Staff's Fact-Finding and Assessment Mechanism is investigating the circumstances of the deaths of civilians in the area of the strike. The IDF regrets any harm to uninvolved civilians during combat," the IDF said in a statement.

The White House has not commented on the attack yet, and the Israeli prime minister’s office has not released a statement.

-ABC News' Ellie Kaufman