It is now almost impossible to access other parts of Chin state where unknown villages may now be in dangers of food shortage and clean water accessibility.
Thousands of people are left homeless and sheltering themselves at relatives' homes and some took refuge at schools, churches and locally managed crisis rescue centres.
The hilltop Chin state capital of Hakha, home to about 40,000 people, is still only accessible by helicopter a week after a series of landslides saw walls of saturated earth collapse onto homes and roads.
About 6,600 people were taking refuge in temporary shelters either too afraid to go home, or with no house to return to, according to Thang.
"Many people are traumatised. People are really afraid of more rain," he said, adding illness had started to spread.
While the state capital has food for several more days, Chin activists raised the alarm over the fate of even more remote communities.
"Food could run out very soon. It's an emergency," Dal Sian Amm, of Chin Natural Resources Watch Group, told AFP.