The incident, which occurred at approximately 3:50 am local time (20:50 GMT Wednesday), was reported to have taken place in the Songinokhakkhan district in the Ulan-Bator region.
The agency is currently conducting an investigation into the source of the fire.
As the cold season approaches, the NEM Agency noted that the number of domestic fires is on the rise as households in the capital's ger districts tend to light up in order to stay warm.
This is due to the fact that over half of the city's population resides in rural districts, which lack access to water, heating, or sanitation.
(With UNI/Xinhua inputs)