Hamas militants on Saturday released four female Israeli soldiers they held captive for 15 months in a planned exchange for 200 Palestinian prisoners or detainees in Israel.It's the second exchange since a fragile ceasefire took effect last weekend, halting the fighting in Gaza for at least six weeks during which dozens of Israeli hostages and hundreds of Palestinian prisoners will be freed while more aid flows in.RELATED STORY | Israel-Hamas agree to ceasefire deal to pause war in Gaza and return hostagesIn return for the four soldiers, Israel should free 200 Palestinian prisoners or detainees, including 120 militants serving life sentences after being convicted of deadly attacks. The first exchange took place Sunday with the release of three Israeli hostages and 90 Palestinian prisoners.Israel's war against Hamas in Gaza has killed more than 47,000 Palestinians, according to Gaza health authorities. The ministry doesnt distinguish between combatants and civilians. The war was sparked by Hamas' Oct. 7, 2023, attack on Israel, which killed around 1,200 people.Israel says it will not allow Palestinians to return to northern Gaza until Arbel Yehoud, one of the dozens of hostages held by Hamas, is released.RELATED STORY | State Department freezes new funding for nearly all US aid programs worldwidePrime Minister Benjamin Netanyahus office said Yehoud was supposed to have been released Saturday as part of the Gaza ceasefire agreement.The four Israeli soldiers, Karina Ariev, 20, Daniella Gilboa, 20, Naama Levy, 20, and Liri Albag, 19, were captured in Hamas Oct. 7, 2023, attack that ignited the war.