Several blazes that kept fire crews busy the past several days remained under investigation on Monday.
Warren fire Chief Ken Nussle said he suspects that at least two fires were intentional - including two blazes days apart at the same structure.
"Sometimes these investigations can take time. But we are talking to neighborhood residents and anyone who might have information," Nussle said on Monday.
There were no injuries reported.
City crews were called about 5 p.m. Sunday to a fire at a vacant house at 615 Sidells Court N.E. - three days after battling a blaze there early Friday morning. Officials said the fire appeared to have started in the garage and then spread to the two-story house.
Nearby residents said a homeless man was living in the house, but no one was found inside.
Fire crews extinguished a fire at the same location about 3 a.m. Friday. That fire also was mainly in the garage area.
Officials said the do not believe Friday's fire rekindled on Sunday, but that it's more likely there was a second fire at the same structure.
"Several years back we had some fires in that same area, not necessarily on Sidells, but off Chestnut. It turned out to be a group of juveniles setting them," Nussle said.
Meanwhile, he confirmed that insurance adjusters were at a house at 209 Washington St. N.W. on Monday to complete a separate investigation into a fire that gutted that house early Friday morning. Nussle said he expects his department's investigation into that blaze to be wrapped up within the next several days. The Trumbull County Auditor's Office website lists former club owner LaShawn Ziegler as a co-owner. Officials said the occupant, who rents the property, was not home when the fire started about 3 a.m.