In theory, in practice they walk into the kill zone and thats it.Of course you can.
If the other side decides they don't want to stop firing and kill their own hostages, that's on them.
But you can have no ceasefire and just say "we will leave the hostages in the public square" if you want.
There is no requirement for a formal ceasefire in order to release hostages.
It's easier, sure, but no one needs a ceasefire to do it.
Initial IDF probe: 3 hostages were shirtless, waving white flag when troops shot them
One of the 3 killed in tragic mistake shouted 'Help' in Hebrew; IDF says soldiers fired against protocols; on Wed., troops found 'SOS' and 'Help, 3 hostages' spray-painted nearby
www.timesofisrael.com