Two people in their 80s were injured Sunday in a fire in a house in the Potomac area of Montgomery County, the county fire department said.

An 85-year-old man was seriously injured and an 87-year- old woman was also injured in the fire about 3 p.m. in the 8100 block of Whites Ford Way, authorities said.

The extent of damage caused to the house was not immediately known.

A fire department spokesman said that preliminary investigation suggested that the fire may have resulted from improperly discarded smoking materials.