After tortuous, weekslong negotiations, Israel and Hamas reached an agreement Thursday for a brief cease-fire that will begin on Friday morning and allow for the release of at least 50 women and children held hostage in Gaza. In return, Israel agreed to a pause in hostilities of at least four days and the release of 150 Palestinian women and minors imprisoned in Israeli jails.

The cease-fire, announced by the Qatar Foreign Ministry, marks the most significant diplomatic breakthrough since Hamas’s Oct. 7 attacks on Israel, which killed 1,200 people, according to the Israeli authorities, and prompted a devastating Israeli invasion of Gaza. It is scheduled to take effect at 7 a.m. local time.

The first 13 hostages will be released to Mossad, Israel’s foreign intelligence agency, apparently in good health, at 4 p.m., according to Qatar, which helped broker the deal. Lists of freed hostages and prisoners will be released day-to-day, with the goal of a further agreement to extend the pause in hostilities and release more hostages.

“The first glimmer of light at the end of the tunnel,” said Majed al-Ansari, a spokesman for Qatar’s Foreign Ministry, in announcing the deal.

The Biden administration played a significant role in pushing for the deal, along with the governments of Qatar and Egypt. The cease-fire was originally expected as early as Thursday morning but negotiators required more time to hammer out details — sticking points included the number of hostages Hamas actually held — underscoring the agreement’s fragility.

But even as the deal came together, the Israeli bombardment continued in Gaza, where at least 12,700 people have been killed, according to health officials in the enclave. Lt. Col. Richard Hecht, an Israeli military spokesman, told reporters, “Until we’re given the order to hold our fire, our operations are continuing.” In some southern Israeli communities, air-raid sirens warning of incoming rocket fire from Gaza still wailed.