Nawaz Nashra recalls grabbing her three-year-old daughter, wrapping her in a bedsheet and running out of their home in central Sri Lanka as a landslide struck, triggered by a deadly cyclone that killed 410 people in the worst floods in a decade.

Nashra and her pregnant sister, who lived with her, spent the next 20 minutes scrambling down the hillside from Alawathugoda village on Friday night, sometimes knee-deep in mud, until they reached a mosque at a lower altitude, where they spent the night.

"It was pitch dark...We could only hear a sound like thunder," she told Reuters. "The house next to ours collapsed as we watched. There was no time to warn anyone."

About 10 houses in the neighbourhood were swept away by Cyclone Ditwah and at least 25 people are feared dead, residents said on Tuesday, when they returned with long poles to dig through the mud and search for bodies.

Deadly storms have swept across South and Southeast Asia in recent days, devastating large parts of Indonesia, Malaysia and Thailand and claiming hundreds of lives.

In Sri Lanka, the Kandy region where Alawathugoda is located has recorded 88 deaths - the highest in the South Asian country - with 150 people still missing. More than 20,000 people have been moved to 176 shelters set up to house them.

Across the country, 336 people remain missing and 1.2 million have been affected, officials said, as hundreds of army and police personnel combed through regions hit by landslides to retrieve bodies.

Authorities on Tuesday used bulldozers and backhoes to clear roads, removing mud and trees to create a path for food and fuel to reach affected areas.

Work was also underway to restore communication links and electricity, which was cut after strong winds snapped transmission lines, officials said.

About 3 kilometers (2 miles) away from Nashra's home, another neighbourhood in the village also bore signs of being struck by landslides, with houses partially damaged and a tangled mess of phones, books, furniture, and clothes visible in the slush.

"They tell us to leave but where do we go? There is a temple nearby but there is only one bathroom for about 100 people. The facilities are not enough," said Manjula Jayalath, 43, a resident of the area.