GAZA, Sept. 2 (Xinhua) -- At least 12 Palestinians, including seven children, were killed in an Israeli airstrike on a camp housing displaced persons in the Al-Mawasi area, west of Khan Younis, in the southern Gaza Strip, Palestinian sources said on Tuesday.

Sources and witnesses said several children were filling drinking water at the time of the Israeli airstrike, which destroyed several tents made of cloth and nylon.

Medical crews recovered 12 bodies -- seven of them children -- and rushed several wounded survivors to nearby hospitals, medics said.

There was no immediate comment from the Israeli army on the airstrike.

Al-Mawasi is designated by Israel as a humanitarian zone and is promoted as a safe area for Gaza residents. It stretches from west of Rafah in southern Gaza to the outskirts of Nuseirat in central Gaza.

Earlier on Tuesday, Avichay Adraee, Israeli army spokesperson, called on residents of Gaza City to head to the Al-Mawasi area ahead of an expected expansion of military operations.

"To all residents of the Gaza Strip, in preparation for the expansion of fighting into Gaza City, we remind you that the Al-Mawasi area will witness the provision of better humanitarian services, especially health services, water, and food," he said in a statement.

"For your safety, we warn that approaching or returning to combat zones or to areas where IDF forces operate exposes you to danger," he added. ■