Police and fire investigators are looking into the cause of three bush fires that may have been intentionally set along the H-1 Freeway in Kapolei Sunday morning.

The brush fires were about a quarter mile apart from each other next to the town-bound lanes of the freeway between the Makakilo on-ramp and the North-South Road off-ramp. No homes or structures were threatened. The cause was undetermined.

Honolulu Fire Department spokesman Kendall Ching said the fires, that burned 3 acres, were reported at 9:11 a.m. Sunday. Seventeen firefighters from six companies and three tankers brought the blaze under control by 9:49 a.m.

Honolulu police shut two town-bound lanes of the freeway at 9:45 a.m. near the North-South Road off­ramp. The lanes were reopened around 12:45 p.m.

On May 18, a Makakilo brush fire destroyed 80 acres adjacent to the H-1 Freeway and threatened nearby homes and prompted voluntary evacuations.