An Israeli security official said the transfer of aid into the territory is halted "until further notice," the first major test of the ceasefire.

As the delicate ceasefire between Israel and Hamas takes hold, some aid has begun flowing into the Gaza Strip, where many Palestinians are returning home and beginning to reckon with the destruction caused by the two-year conflict.

Israel has reopened two crossings in Gaza, while the key Rafah crossing will stay closed to the movement of people until further notice.

Israeli fire killed three people near a ceasefire line in Gaza on Monday, medics said, with U.S. envoys expected in Israel to try to push forward the fragile truce that faced its gravest test so far over the weekend.

Detainees seek to return to their normal lives in Gaza after being freed from Israeli captivity, where some say they faced torture and beatings.

Israel has said it will resume enforcement of the ceasefire after launching air strikes on Gaza in response to what it called Hamas's "blatant violation".

By Nidal al-Mughrabi and Steven Scheer CAIRO/JERUSALEM (Reuters) -Israeli fire killed three people near a ceasefire line in Gaza on Monday, medics said, with U.S. envoys expected in Israel to try to push forward the fragile truce that faced its gravest test so far over the weekend.