Crews last night first fought to contain the blaze, but it began burning along a new fire line this morning, threatening farm lots in the valley.

A total of 15 Honolulu Fire Department units were dispatched to the area of the fire, said Capt. Richard Soo, department spokesman.

The blaze started at 8:21 p.m. last night near Angel's Junkyard, 85-1570 Wai'anae Valley Road.

State forestry fire crews joined the fight this morning, concerned about native plants that flourish deep in the valley; however, the south-southwest bearing of the fire line doesn't appear to threaten the native forest, Soo said.

What is threatened is a range of agricultural businesses, including floral nurseries and livestock operations, Soo said.

The department has not evacuated any residents, he said.

"But people with respiratory problems might have some discomfort," he said. "We would like them to seek medical attention. And, although we are not ordering an evacuation,they might like to remove themselves from the area."

More details to come.