Relentless rain has lashed south-central Vietnam since late October and popular holiday destinations have been hit by several rounds of flooding.

Whole sections of coastal Nha Trang city were inundated last week, while deadly landslides struck highland passes around the Da Lat tourist hub.

In the hard-hit mountainous province of Dak Lak, 61-year-old farmer Mach Van Si said the floodwaters left him and his wife stranded on their sheet-metal rooftop for two nights.

"Our neighborhood was completely destroyed. Nothing was left. Everything was covered in mud," he told AFP on Sunday.

By the time they climbed a ladder to their roof, Si said he was no longer scared.

"I just thought we were going to die because there was no way out," he said.

More than 60 deaths recorded since November 16 were in Dak Lak, where tens of thousands of homes were inundated, the environment ministry said in a statement.

Four communes in Dak Lak were still flooded on Sunday, the ministry said.

More than 80,000 hectares of rice and other crops across Dak Lak and four other provinces were damaged in the last week, with over 3.2 million livestock or poultry dead or washed away by floodwaters.

Authorities have used helicopters to airdrop aid to communities cut off by flooding and landslides, with the government deploying tens of thousands of personnel to deliver clothing, water-purification tablets, instant noodles and other supplies to affected areas, state outlet Tuoi Tre News said.

Severe flooding in southern coastal Khanh Hoa province washed away two suspension bridges last week, leaving many households isolated, the outlet said, citing officials.

Several locations on national highways remained blocked on Sunday due to flooding or landslides, according to the environment ministry, and some railway sections were still suspended.

More than 129,000 customers remained without electricity, after more than a million were without power last week.

The environment ministry on Sunday estimated economic losses of $343 million across five provinces due to the floods.

Natural disasters have left 279 people dead or missing in Vietnam and caused more than $2 billion in damage between January and October, according to the national statistics office.

The Southeast Asian nation is prone to heavy rain between June and September, but scientists have identified a pattern of human-driven climate change making extreme weather more frequent and destructive.