Authorities say hundreds of homes were buried by mud and rubble sent cascading down hillsides.
Chittagong: Rescue workers battled Wednesday to reach victims of landslides, described as the worst in Bangladesh's history, as the death toll from the disaster rose to 152.
Villagers in some of the worst-hit areas used shovels to try to dig bodies out of the mud that engulfed their settlements as they slept.
Authorities say hundreds of homes were buried by mud and rubble sent cascading down hillsides after monsoon rains dumped 343 millimetres (13.5 inches) of water on the southeast of the country in just 24 hours.
Disaster Management Department chief Reaz Ahmed said the landslides were the worst in the country's history and warned the death toll would rise as rescuers reached cut-off areas.
Khodeza Begum narrowly survived the disaster, which destroyed her home and killed 11 people in her village.
She told a local news website how she emerged from her home just after dawn on Tuesday to see the mountainside collapsing in front of her.
"As I came out, I saw a huge slab of earth rolling down from the hill. Instantly I got all my relatives out of their homes," she said.
"My house was buried under mud within moments. I have never seen a disaster like this in my life."
Firefighters in the worst-hit district of Rangamati recovered six more bodies on Wednesday after clearing mud with shovels and water pumps.
"The bodies were three to five feet deep in mud. We pumped water at a force to clear the mud," said Didarul Alam, fire services chief for Rangamati district
The firefighters had pulled 18 people out from under the mud on Tuesday, but did not have the manpower to reach all the affected areas.
Alam said his team had been able to reach more areas on Wednesday after 60 reinforcements arrived from neighbouring Chittagong.
Authorities have opened 18 shelters in the worst-hit hill districts, where 4,500 people have been evacuated, a minister said.
The monsoon rains came two weeks after Cyclone Mora smashed into Bangladesh's southeast, killing at least eight people and damaging tens of thousands of homes.
South Asia is frequently hit by flooding and landslides in the summer with the arrival of the annual monsoon rains.
Extreme weather in the far north-eastern Indian state of Mizoram along the border with Bangladesh left 12 people dead, an official there said Wednesday.
"Many people are reported missing. Hundreds of houses, roads and some mobile towers have been damaged in the flooding and landslides in the region," N Chakhai, the state's head of disaster management, told AFP.
More than 200 people were killed in Sri Lanka last month when the monsoon triggered landslides and the worst flooding the island has seen in well over a decade.
Experts in Bangladesh said unplanned development in vulnerable areas was making the annual rains more deadly.
"There is a backlash effect. These things accelerate the pace of the disaster and make it more fatal," S.M.A. Fayez, an environmental science professor at Dhaka University, told AFP.
Rescue work has been hobbled by heavy rains, which have cut transport links to some remote areas.
The army said thousands of troops stationed in the affected districts as part of efforts to quell a long-running tribal insurgency had joined the rescue efforts.
"Our soldiers based in all parts of the Chittagong Hill Tracts have participated in the rescue operations," armed forces spokesman Lieutenant Colonel Rashidul Hasan told AFP.
Rangamati district chief Manzurul Mannan said 104 people had been killed there and 200 injured, some of them seriously. At least 37 people died in Chittagong, scene of a major landslide in 2007 that killed 127 people.
Among the victims in the latest disaster were two fishermen who drowned off the coast of Cox's Bazar after their boat apparently capsized. Other trawlers and their sailors were still missing.
As rain pounded Cox's Bazar for a third day, police confirmed that a father and daughter had been killed when a landslide buried their home.