OAKLAND -- A stubborn house fire in the Oakland hills Thursday night was likely caused by chemicals used for refinishing furniture, a fire official said.

Oakland Fire Department Battalion Chief Robert Lipp said Friday that the two-alarm blaze was tough to control because fire was hidden in walls and underneath the four-story house in the 7000 block of Norfolk Road.

"The fire was not the worst I've seen or the biggest, but really frustrating," Lipp said. "It was a very stubborn fire."

No one was home at the time and there were not injuries to residents, firefighters or pets, Lipp said.

Lipp said the occupants -- two adults and three children -- were not home when firefighters were called about 6 p.m. Thursday, but the residents returned home while the fire was burning.

Lipp said it's believed that rags soaked in chemicals and left in an enclosed basement storage area likely sparked the fire. Someone who lived at the home was refinishing a piece of furniture, he said.

But the cause remains under investigation. Lipp said fire officials don't have a damage estimate yet.

"It's not quite a tear down, but the damage was extensive," he said.

A neighbor called the fire department, but Lipp said the fire could have been burning for several hours before the neighbor noticed the smoke streaming from the roof.

The fire sent large plumes of gray smoke into the sky and took roughly 36 firefighters to contain.

Reach Kristin J. Bender at kbender@bayareanewsgroup.com. Follow her at Twitter.com/kjbender.