The Countdown star, who has two young daughters, told Sky News the events were "unthinkable," and her thoughts were with all the families "going through this most horrendous of times".

An unprecedented attack by Hamas on 7 October killed at least 1,400 Israelis, and retaliatory air strikes in Gaza by the Israeli military have killed more than 2,800 Palestinians.

Follow live: UN operation 'on verge of collapse' in Gaza

Hundreds of thousands of Palestinians are now facing dwindling food and water supplies, humanitarian aid unable to pass the Egyptian border, while the fate of 199 hostages being held in Gaza remains unknown.

Speaking at the Women Of The Year Awards, which celebrates inspirational women in education and technology, Riley said: "We can't as civilised people condone acts of terrorism. It's 2023.

"When we say never again, we mean never again. We don't expect people to turn up in jackboots and swastikas. We mustn't accept terrorism wherever it comes from. My heart breaks for all the families in the world, who are subject to horrible politics and extremism.

"I found myself driving in the car the other day, and my children were in the back of the car and they were screaming and crying because one of them had a plastic plane and the other one wanted it.

"And I literally just stopped and had this moment of peace and happiness. But my children were screaming about a plastic plane. [The situation in Gaza] is unthinkable."

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Riley said events like Women of the Year, which celebrate "every woman from every background" shows that people from very different backgrounds "can get on in harmony".

"It's hard at times, but we can speak to each other, engage."

Praising the work of Jewish-Muslim women's network Nisa-Nashim - which means women in both Arabic and Hebrew - she said such organisations were key to putting an end to future conflict.

"Now, it's more important than ever not to let things divide us. Everywhere in the world, men are ruling the world and even looking at peace protests in Jerusalem two weeks ago, where Palestinian women and Israeli women marched together, that that's the only thing that's ever going to bring peace to anyone."

In July, Riley was awarded an MBE for services to Holocaust education and fighting antisemitism.

Now, taking stock of that recognition, she said: "Nothing hits home more than now that services to Holocaust education means making sure that things like this don't happen again.

"I'm so passionate about projects like these that bring people together. That have people in person speaking to each other. That's the way forward. And we just have to continue to remind ourselves why we do things and what we want to achieve."