Authorities believe "improperly discarded smoking material" is the cause of a 6-acre fire in southeast Travis County near about 20 homes Thursday.

At around 1 p.m., the Austin Fire Department said their department along with ESD 11 Travis County Fire Rescue has contained the fire, which was moving toward the roadway and the homes at Ross Road and Pierce Lane near Austin's airport.

The fire, which is now under control, was probably caused by "multiple improperly discarded smoking materials," AFD tweeted: