Fire officials say the fire was set underneath the mobile home. (CBC)

Police are investigating a suspected arson that destroyed a mobile home and left two people homeless on Demarco Street in Sydney Mines, N.S.

Fire marshal Vince Penny said it's the second fire at the home in as many days.

He said there was no one inside during the first fire, which caused minimal damage. A woman and her teenaged daughter moved in Thursday, a few hours before the second fire began. He said they escaped unhurt.

"That hour of the morning, usually people would be in bed asleep. Thankfully the fire was on the outside of the trailer," he said.

"They were lucky to escape because trailers are extremely combustible and fire can spread quite readily through them."

Penny said the fire began underneath the mobile home.

Lawson States, the owner of the mobile home, said the source of the blaze was what appeared to be a firebomb.

"It was a little jar, with holes punched in it. Must've been soaked on with gasoline or something," he told CBC News. "I would like to know who done it, they're taking people's lives into their hands."

Cape Breton Regional Police Staff Sgt. John O'Rourke said he's concerned about the repeated incidents.

"Whether it was an adolescent figuring it's pre-Halloween and going to have some fun, or it's just somebody that has some issues, our concern is that property is being damaged and possible lives will be lost," he said.

States said the mobile home was not insured and will have to be demolished.