Israeli forces have told people to leave eastern Rafah in the Gaza Strip. About 1.2 million people have been sheltering in the southern city.
They are poised to push for a ground operation in Rafah as negotiations with Hamas on a pause in the fighting and hostage releases are stalemated.
Israeli forces used social media, fliers and other means on Monday to urge people to leave. The military called on people to evacuate immediately for their safety. They said they were about to act against terror organizations in the area.
The notification does not mention the scale or duration of the operation it warns about.
Washington has repeatedly protested Israel's calls for an operation in the area. Still, Israeli Defense Minister Yoav Gallant reiterated the necessity of a ground assault on a telephone call with US Defense Secretary Lloyd Austin.
Meanwhile, no progress was reported for talks between Israel and Hamas in Egypt over the weekend. Egyptian media said Hamas is expected to study what they discussed during the negotiations.
Israel has said it wants to fight until it eliminates Hamas, while Hamas wants complete ceasefire.
As negotiations stalled, 22 people including eight children were killed in Israeli attacks from Sunday to Monday. If Israel goes ahead with a ground operation in Rafah, it is feared that many more civilians will be killed.