Residents in part of Khan Younis in the southern Gaza Strip have left the area following an Israeli evacuation order, many by foot.
The Israeli military said on Monday that people in the eastern part of Khan Younis should immediately leave.
Local media have reported that Israel conducted an attack against the area, causing a number of deaths and injuries.
Footage taken in western Khan Younis by an NHK crew shows people evacuating, most of them on foot. Some small children were carrying household goods. A wounded person and the body of a child were being transported to a hospital.
One resident said he didn't know where to go, and that evacuees would have to spend the night on streets. He added that he wonders whether the evacuees -- civilians -- have done something wrong.
The US-based Institute for the Study of War says Hamas is reconstituting its forces in Khan Younis after the Israeli military withdrew from the area in April.
Observers say that if Israeli forces start a clearing operation there, the humanitarian situation would worsen further.