Honolulu firefighters are battling a brush fire near Makua Cave that has spread out over 20 to 30 acres and forced the closure of Farrington Highway in both directions.

The blaze was first reported at 8:13 p.m. Six fire companies, two tankers and a battalion chief are at the sight and are working to contain the fire, expecting that it will burn itself out as it climbs the mountain, according to Hawai'i Fire Department spokesperson Capt. Robert Main.

There are no houses or other structures in the immediate area.