OAKLAND (KPIX 5) – A fire broke out at an apartment complex in Oakland early Friday morning, displacing more than a dozen people, according to authorities.

Fire officials told KPIX 5 that the fire started around 4:00 a.m. at a building on the 3800 block of Harrison Street near Bayo Vista Avenue.

Officials said the fire started on the first floor of the complex, spreading to six units.

All residents were able to escape the burning building safely. Two people were treated for smoke inhalation, but were not hospitalized, officials said.

Firefighters were able to put out the flames shortly after 6:00 a.m.

Officials said the fire may have been caused by a blanket that caught fire next to a wall heater, but the fire remains under investigation.

The American Red Cross is on scene assisting 14 residents.