The fire broke out at a 10-story apartment building in the southern district of Khan-Uul at around 7:02 a.m. local time (2302 GMT) before firefighters rushed to the scene, Xinhua reported.
"Unfortunately, five members of a family, including four children, lost their lives. Also, two others, including a worker of the emergency agency, breathed their last in a local hospital," the emergency agency said in a statement.
An investigation is underway to find out the cause of the fire, it added.
AMK/PR