The fire, reportedly started around 1am in the middle of the night, damaged seventeen shops and four office rooms of the building in Falam's market.
An eyewitness said it was too late when people woke up and tried to put out the blaze, adding: "A fire engine arrived and residents as well as police made an attempt but in vain."
No casualties were reported in the midnight incident.
The building managed by the Cooperative Department was reconstructed in 2010 after it was once burnt down in the past, according to the Chin World Media.
As of today, it is not yet known as to who and how the fire started.
Reporting by Thawng Zel Thang