Vietnamese emergency services were Monday seeking to reach isolated and flood-hit northern communities after tropical storm Kammuri left at least 100 people dead and 50 missing over the weekend.

Flash-floods and landslides since Friday have cut major highway and rail links to the mountainous region bordering southern China. The heavy downpours have also knocked over trees and telephone and electricity lines.

Thousands of troops and disaster relief personnel were using trucks and boats to deliver water, food and medicines to residents in flooded villages, with some people stranded on roofs by the murky waters.

"We have reached some areas that had been isolated for two days," Thao A Tua, a disaster relief official from worst-hit Lao Cai province, told AFP.

"We are focusing on finding the people still missing. It's bad, we are afraid they are dead and we'll have to recover their bodies."

Hundreds of foreign tourists were stuck in the scenic northern region, which is dominated by ethnic minorities, but none were reported to be among those killed or the 38 people injured in the disaster, officials said.

The rains had stopped Monday but severed roads hampered relief efforts.

"The traffic jams are very serious... and many vehicles and passengers are stuck," central emergency relief authorities said in a report. "Local inhabitants face many difficulties because there is not enough food."

The Central Committee for Flood and Storm Control also ordered local authorities to check dykes along the swollen Red and Thai Binh Rivers.

Across the northern region, more than 300 houses were destroyed, over 4,200 buildings were flooded and suffered water damage, and about 8,700 hectares (21,500 acres) of crops were wiped out, said the central government.

In worst-hit Lao Cai province, 37 people have been killed and 40 listed as missing, many feared dead under mountains of mud and rubble that have slid down water-logged mountain sides and buried houses.

"This has been the worst flooding since 1971," said Tran Anh Van, a provincial disaster official of Yen Bai, where 35 people were killed and five remained missing. "Two more bodies have been recovered. They had been swept away in the strong currents."