Seven Fire Department companies were keeping an overnight watch on a Makaha Valley brushfire that intensified yesterday afternoon, moving closer to homes at the Mauna Olu gated community and Makaha Valley Towers apartments.

The fire, which began Friday, has burned an estimated 500 acres, including 200 yesterday, said Fire Department spokesman Capt. Earle Kealoha.

Kealoha said the fire had been moving up the mountainside most of yesterday but started moving downslope about 5:30 p.m. following a shift in the wind.

The fire was burning behind Mauna Olu and near the Kaneaki Heiau, witnesses said. It was less than two miles from Makaha Valley Towers at one point, Kealoha said.

The fire was also threatening endangered plants and animals on the top side of the ridge, Kealoha said. He said the department was working to contact Army environmental officials.

Earlier yesterday, a helicopter made water drops while seven engine companies and three tankers fought the blaze on the ground. Two federal engine units and a battalion chief were also at the scene.