Tens of thousands of Rohingya Muslims who had fled persecution in neighbouring Myanmar are now homeless.

The authorities in Bangladesh say they have begun an investigation into how the fire started.

At the camp in Cox's Bazar are South Asia correspondent Rajini Vaidyanathan reports.

Each pillar marks out what was once a makeshift hut.

The smoldering remains are all that's left for thousands of refugees is cramped and congested camp now reduced to ash.

Zubaydah Beggar lost her home in the fire.

My two sons are missing.

I'm looking for them everywhere, she said.

The massive fire started in one section of the settlement on Monday afternoon, but soon spread, destroying homes, schools and hospitals.

Refugees ran for their lives.

Rohingya Muslims, who fled a military crackdown in their home Myanmar more than three years ago, once again on the move.

Johanna has been searching the camps with one of her sons trying to find six-year-old Mohammed, who has not been seen since the fire broke out.

I don't know whether he's dead or alive, she said.

Please, God, help me find my son.

I just want him back.

Close to a million Rohingyas live in the world's largest refugee camp, already in dire poverty, they're once again struggling to survive.

Aid groups say more than 45,000 refugees have now been left homeless.

Well, I think that the fire is a continued symptom of the larger deterioration within the camps.

Um, it's three years on.

This is a protracted refugee crisis, obviously a failure of the international community to find a solution.

With the ongoing military coup in Myanmar, Rohingya refugees can't go home any time soon. With their temporary homes now destroyed, their life in limbo continues. Rajini Vaidyanathan, BBC News Daily.