SELAH, Wash. -

About 150 more firefighters are attacking a wildfire Wednesday that burned about 15 square miles of grass and brush and threatened homes near Selah in the Yakima Valley in south central Washington.

More firefighters from state and federal agencies were dispatched as the state mobilized to help about 100 firefighters who responded Tuesday to the fast-moving fire.

A Department of Natural Resources dispatcher says the fire slowed and did not move in the overnight hours.

Officials say the fire threatened about a dozen homes Tuesday and destroyed at least two outbuildings. The fire may have been started by target shooting, igniting dry grass.