[Video transcript]
Families rush from the fighting in Gaza's south, desperately seeking safety as gunfire rattles in the distance.
One mother pushes her sick son on a hospital bed.
For this family, it's their third time being forced to move. It's like this everytime, they say.
Israel has previously told people to move to the south of the Gaza strip, which is now the scene of intense fighting.
A reported tank attack on a UN facility killed at least 13 people and injured dozens.
Around 70,000 people are estimated to be sheltering in or around the complex.
Israel has only now warned them to leave.
(Tamara Alrifai, UNRWA)
''Now in terms of how realistic it is to ask up to 70,000 people to evacuate in less than 24hours, it is extremely unrealistic to be able to expect all of these people to truly leave while the active fighting is still happening — and to leave safely.''
Hospitals in the area are struggling to provide basic care, with many of the injured unable to get to them for help.
(Tamara Alrifai, UNRWA)
"There are three main hospitals in Khan Younis, they're all encircled currently: The Nased, the Al-Aqsa and Al-Amel, these are the main hospitals in Khan Younis and it's extremely hard to access them. In fact, It's extremely hard to access that part of west Khan Younis anyway."
Israel believes senior Hamas officials — and Israeli hostages — are in tunnels under Khan Younis.
Thousands of people are now trying to leave the city, with many heading to nearby Rafah —
joining the more than 1 million displaced Palestinians who have already fled there.