South Africa said on Tuesday that it has asked the International Court of Justice to consider whether Israel's plan to extend its offensive into Rafah required additional emergency measures to safeguard the rights of Palestinians.

The move came amid mounting concerns within the international community over Israel's plan to extend ground operations into Hamas' southernmost stronghold. More than one million people are taking shelter in Rafah.

The World Health Organization's Regional Director for the Eastern Mediterranean, Hanan Balkhy, posted photos on her social media account on Monday showing a crowd of people at a hospital.

She wrote, "Hospitals in Rafah are overwhelmed with limited supplies. There are more patients than beds available. Health workers are overstretched but continue to persevere."

UN Secretary-General Antonio Guterres told reporters on Tuesday that "the core of the humanitarian system" is located in Rafah, and that an all-out offensive there would have "devastating consequences."

The Israeli military on Tuesday posted a video on social media of what it says is the inside of an underground tunnel where the leader of Hamas, Yahya Sinwar, and his family had been hiding until recently.

An Israeli soldier says in the video that they fled when they heard that the Israel Defense Forces were approaching.

A video was also released of Israel Defense Forces Chief of the General Staff, Lieutenant General Herzi, Halevi visiting an area near the border of Gaza and Israel.

The Israeli military says it will be very difficult to take back the hostages and end the war unless it continues its attacks on Hamas.