Hamas released all 20 of the last living hostages on Monday, the Israeli military said, as part of a breakthrough ceasefire after two years of war between Israel and Hamas in the devastated Gaza Strip.

Buses carrying dozens of freed Palestinian prisoners drove to the West Bank city of Ramallah and the Gaza Strip, the Hamas-run Prisoners Office said, as Israel released more than 1,900 prisoners.

U.S. President Donald Trump is in the region to discuss postwar plans and the U.S.-proposed deal with other leaders. A surge of humanitarian aid was expected into famine-stricken Gaza, where hundreds of thousands of people have been left homeless.

While major questions remain about the future of Hamas and Gaza, the exchange of hostages and prisoners marked a key step toward ending the deadliest war ever between Israel and the militant group.

What to know:

• World leaders meet in Egypt: Trump and Egypt’s president chaired the summit in Sharm el-Sheikh, a resort city in the Sinai Peninsula where more than 20 world leaders gathered to discuss regional stability, ending the Israel-Hamas war, and how to rebuild and govern the devastated Gaza Strip.   

• Who are the Palestinians released by Israel? Among the nearly 2,000 freed Palestinians are around 1,700 detainees from Gaza who Israeli troops seized during the war and held without charge. Israeli forces detained thousands of Palestinians in raids on shelters and hospitals and at checkpoints. Also among those released were 250 Palestinians sentenced to prison terms, most of them convicted for deadly attacks on Israelis dating back decades as well as others convicted on lesser charges, according to Israel’s Justice Ministry. Of those, Israel exiled 154, sending them to Egypt, where officials said they will be sent to third countries.