Tens of thousands of Palestinians streamed into Gaza’s most heavily destroyed area on Monday after Israel opened the north for the first time since the early weeks of the war with Hamas, a dramatic reversal of their exodus 15 months ago.

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.

An agreement has been reached between Israel and Hamas that involves the release of additional hostages and the return of Palestinians to the northern part of the Gaza Strip.

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.

NBC News drone video showed large crowds waiting to pass the Israeli-controlled Netzarim Corridor to return to their homes in northern Gaza. Israel did not withdraw from the area after accusing Hamas of violating the ceasefire when female civilian hostage Arbel Yehud wasn't released.