Another suspected arson fire at a vacant home in Thornton Park was discovered by a neighbor on Tuesday afternoon. (Video by FOX35)

Another suspected arson fire at a vacant home in Thornton Park was discovered by a neighbor on Tuesday afternoon, according to the Orlando Fire Department.

It's the sixth suspicious fire to be reported between late Saturday and early Sunday and the 13th since June 5 in Thornton Park, Colonialtown and other established downtown neighborhoods.

Assistant Chief Keith Maddox said a neighbor smelled something burning at the vacant house next door on Shine Avenue late Saturday, but didn't see anything.

The neighbor went into the backyard of the vacant house on Tuesday afternoon and saw someone set some wooden fencing in the crawl space of the house on fire, said Maddox.

The fire did not spread and the damage was minimal, he said.

"Our arson investigators are looking into it," Maddox said.

The Orlando Police Department also responded to the scene.

Maddox said the fire was similar to the others in that the exterior of the house was set on fire. Other fires were reported at homes on Christor Place, North Hampton Avenue, Park Lake Street, Lake Highland Drive and North Hill Avenue.

Most fires have been lit in the crawl space of the home and have happened between 10 p.m and 2 a.m., said Orlando City Commissioner Patty Sheehan.

The state fire marshal's office is investigating the downtown Orlando fires and five other suspicious fires in and around the historic district of Sanford. Authorities on Monday said the Sanford and Orlando fires have similarities, but declined to say what those were.

On July 3, Sanford's historic Little Red School House was destroyed in a fire that investigators called arson. There were suspicious fires both before and after the one at the school house that could be related, officials have said.

Anyone with information on the fires is asked to call the Crimeline at 1-800-423-TIPS1-800-423-TIPS.

dharris@tribune.com or 407-420-5471407-420-5471