HILO, Hawai'i — Fire officials continued to mop up three runaway brushfires burning on the west side of the Big Island yesterday, but no homes or businesses were threatened.

Troy Kindred, Big Island Civil Defense administrator, said five of the fires believed to have been deliberately set early Sunday morning had been contained by Sunday night.

The firefighters were still battling the remaining fires at Puako, Kawaihae Village and off the Akone Pule Highway in North Kohala, according to fire and civil defense officials.

The Puako and Kawaihae fires together burned 2,100 to 2,400 acres and were both considered 50 percent contained. The Akone Pule fire was considered 70 percent contained.

At Puako, "this is going to be an ongoing fire probably for at least a week because of the size of the fuel, a lot of heavy kiawe," said Fire Chief Darryl Oliveira. "The more secure we can make the break, the less likely it is that something will escape and run away."

An estimated 400 Puako residents were evacuated Sunday morning because of the thick smoke from the fires, but were allowed to return to their homes Sunday night. Oliveira said the smoke conditions were "light to moderate" in the Puako area.

The firefighting effort was complicated somewhat by archaeological sites in the Puako area, and Kindred said fire crews in some areas used saws to clear brush instead of simply bulldozing the area.

Oliveira said a cultural expert from the Mauna Lani Resort helped fire crews mark archaeological sites so that bulldozer operators could avoid the areas.

The work at Puako mostly involved improving two existing firebreaks to protect homes along the coast while the fire consumes the available fuel of green kiawe and burns itself out.

In Kawaihae, firefighters cut trees that were too close to one home to protect the structure, and continued to make improvements to firebreaks, Oliveira said.

Fire crews also worked to complete breaks at the Akone Pule fire, which had consumed about 200 acres.

Kindred said county dispatchers received calls throughout Sunday night from worried residents who could see flames from their homes and wanted to know what they should do.

"As far as we know, there is no structural damage from any of these fires," Oliveira said.

The Federal Emergency Management Agency yesterday announced it has authorized the use of federal money to help fight the fires, meaning FEMA funding will be available to pay 76 percent of eligible firefighting costs. The Puako fire is the fourth in Hawai'i this year to qualify for a fire management assistance grant.

Reach Kevin Dayton at kdayton@honoluluadvertiser.com.