Officials said the fire apparently started in one of the 34 camps - which span about 8,000 acres of land - before spreading to three other camps, with refugees fleeing the shanties in the Cox's Bazar district.
At least five people are feared dead and more than 20,000 Rohingya have fled a huge blaze engulfing shanty homes at refugee camps in southeastern Bangladesh, in the third fire to hit the settlements in four days.
Nearly one million of the Muslim minority from Myanmar - many of whom fled a military crackdown in their homeland in 2017 - live in cramped and squalid conditions at the camps in the Cox's Bazar district.
Officials said the fire apparently started in one of the 34 camps - which span about 8,000 acres (3,237 hectares) of land - before spreading to three other camps, with refugees fleeing the shanties with whatever belongings they could carry.
Thick columns of smoke could be seen billowing from blazing shanties in video shared on social media, as hundreds of firefighters and aid workers battled the flames and pulled the refugees to safety.
"It is a massive fire. At least 20,000 people fled their homes as the fire spread," Cox's Bazar administrator, Mamunur Rashid, said.
"We doused the fire in one place and it spreads to other places."
Gazi Salahuddin, a police inspector, said the fire was doused at around mid night and officers have heard that five people including three children and two women have died from the fire.
"We heard five people have died from the fire and their bodies are in the camps," Salahuddin said, adding police can't put out any statement unless they recovered the bodies.
Relocation of refugees
Another 3,000 Rohingya refugees have been relocated by Bangladesh to a remote silt island in the Bay of Bengal, according to officials, bringing the total number taken to the new settlement to more than 10,000.
Dhaka wants to relocate 100,000 Rohingya from squalid border camps in southeastern Bangladesh, where nearly a million of the Muslim minority have lived in crowded conditions since fleeing a 2017 military offensive in neighbouring Myanmar.
About 2,000 more refugees were moved to Bhashan Char in late February and followed by another 1,000, Anwarul Kabir, a senior officer with the Bangladesh navy said.