AMNA NAWAZ: In the day's other headlines: Hamas is still reviewing the U.S.

plan to end the war in Gaza.

But the war continues, and tonight Israel blocked a flotilla of ships trying to break through Israel's blockade of humanitarian aid to Gaza.

Nick Schifrin reports.

NICK SCHIFRIN: Hamas might no longer control Gaza's streets, but, tonight, it controls the war's fate.

Arab mediators tell "PBS News Hour" they have held positive meetings with Hamas, but the group needs more time and is concerned about requirements to disarm and release Israeli hostages before Israel withdraws from Gaza.

And so Hamas faces a choice, end the war and its brutal toll or hold out for a better deal, leaving Gazans vulnerable to Israel's promise to occupy all of Gaza City.

Residents and rescue workers who remain in the city today face their fate.

A strike on a U.N.

school turned shelter that Israel said targeted Hamas left a child who's seen so much in shock.

Some 400,000 Gaza City residents have fled, today packing the sole remaining road to the south.

Israel warned this was their -- quote - - "last opportunity" to leave Gaza's city.

And so 28-year-old Ahmed Arafat loaded his cart, taking what he could, leaving behind what his family said he must.

AHMED ARAFAT, Displaced Palestinian (through translator): I did not want to leave.

My family is still in the north, and my father sent me to the south to drop my uncle and not come back.

What can we say?

We are tired.

Our lives are tragic, and the situation is catastrophic.

We pray to God that Hamas agrees and that Israel agrees.

I mean, I am 28 years old and I have not done anything in my life.

NICK SCHIFRIN: As he drove into an uncertain future... WOMAN: This is the Israeli navy.

NICK SCHIFRIN: ... 85 miles to the West, the Israeli navy intercepted a flotilla that was sailing toward Gaza.

MAN: We carry crutches.

We carry baby formula for the people that you have been starving to death.

NICK SCHIFRIN: Israeli forces boarded multiple vessels, detaining those on board, including human rights activist Greta Thunberg, as posted by Israel's Foreign Ministry.

More than 40 boats had been trying to break Israel's maritime blockade of Gaza with hundreds of people from all across the world.

They set off last week from ports in Spain, Italy, Tunisia, and Greece carrying humanitarian aid toward Gaza and escorted by Spanish and Italian naval ships and Turkish drones.

David Adler spoke to us before the interception.

DAVID ADLER, Progressive International: We're now reaching the final hours of this mission, the largest humanitarian convoy ever to traverse the Mediterranean Sea, carrying critical humanitarian aid for the starving people of Gaza.

NICK SCHIFRIN: Adler is a Jewish American activist, part of the Sumud Flotilla coalition.

DAVID ADLER: If the governments of the world won't do something to end this genocide, well, then ordinary people are going to have to take humanitarian matters into our own hands.

We cannot let Israel normalize a state of play in which children are murdered by the day with impunity.

And that's why we're here on these boats, and that's why we're approaching the shores of Gaza.

NICK SCHIFRIN: But as it has done in the past, Israel used its military to block activists trying to reach Gaza from the sea and tonight continues to wage war as it awaits Hamas' reply.