The brush fire that diverted flights from Lihue Airport flared up again early Sunday, the Kauai Fire Department said.

Engine 3 and a battalion chief responded to a flare-up at 3 a.m., doused the flames and saturated the area with water.

At about 8:44 a.m., more fire crews and personnel from the Kauai County Department of Public Works returned to the scene. The public works crew used a bulldozer and a front-end loader to move the debris around while the firefighters thoroughly soaked the exposed areas.

They left the scene at approximately 11:44 p.m., but there was another flare-up at 2:26 p.m. and yet another a couple of hours later, the county said.

About 40 acres was blackened.

The cause of the fire, which broke out at 8:21 a.m. Saturday, was undetermined. But it put enough smoke in the area to prompt controllers to divert at least three flights.