An Israeli air attack has killed 12 Palestinians, including nine members of one family, in a designated “safe zone” after they followed Israel’s evacuation orders to leave eastern Khan Younis, the Associated Press reports.

The United Nations estimates that up to 250,000 people have been affected by Israel’s military order for people to leave areas near the southern city of Khan Younis as the total number of displaced people in Gaza is estimated to have reached 1.9 million.