Israel on Monday began permitting thousands of Palestinians to return to the devastated northern Gaza Strip for the first time since the early weeks of the 15-month conflict between Israel and the militant group Hamas. The move comes as part of a fragile ceasefire agreement currently in place.

Palestinian officials say more than 650,000 displaced people were blocked from entering the northern Gaza Strip, according to Reuters. Israel blocked access to the region after it accused Hamas of failing to release 29-year-old Arbel Yehud during an agreed upon hostage-prisoner exchange.