A 4 p.m. rubbish fire on Nimitz Highway under an 'ewa-bound viaduct near Middle Street yesterday capped a day of incendiary activity that Honolulu Fire Department Capt. Robert Main described as "a little out of the ordinary."

Main said HFD was called to as many as a dozen similar fires — all of which were quickly contained by firefighters.

"We've been having a lot of small, spot brushfires and rubbish fires here and there," Main said. "The Nimitz fire is the biggest we've had today."

"It was an accident," he added. "There seems to be a homeless encampment under the viaduct, and they were cooking with propane burners and they lit some of their belongings on fire."

No one was injured, he said.

Main said the Manoa fire near UH that started Thursday and burned through Friday appeared to be extinguished by yesterday. "It seems to be pretty well out," he said.

On Friday afternoon, Big Island firefighters and a helicopter saved two homes in North Kohala on Puakea Bay Ranch from a brushfire that may have been started by tractor mowers igniting dry vegetation. The fire blackened 10 acres, said Hawai'i Fire Capt. Greg Kane.

And on Kaua'i yesterday, firefighters fought a blaze in a huge compost pile that was ignited by spontaneous combustion behind Kaua'i Nursery and Landscaping in Puhi. Some 14 firefighters responded to the 2:16 p.m. alarm, assisted by KNL workers using a caterpillar, backhoe, loaders and excavator. No lives or structures were threatened. The fire was under control by 3:30 p.m.

Reach Will Hoover at whoover@honoluluadvertiser.com.