UPDATE SATURDAY: Residents are worried four fires - each the size of about five football fields - burning in the Kirkwood area early on Friday evening were deliberately lit.
Customers across the road from Koowin Dr, at Woolworths, were also concerned about the fire as it crept up the hill.
Brett Knopke, who lives on the road where one of the fires burnt, said he believed it was the act of a fire bug.
"Kids are always driving around here running amok," he said.
He said he would backburn his own 6½ acre property this weekend, in preparation for the warm summer.
Gladstone Fire and Rescue station officer Graham Smith said his fire crews had responded to the four grassfires, all of which were reported at 4.30pm.
"There was three here at Kirkwood and one at Callemondah," he said.
"It's strange that four fires would start in such a short period of time so close together," he said.
Sergeant Peter Stone said Gladstone police were investigating. "The sheer number of the fires appears to be suspicious," he said.
"We don't have anyone to charge at the moment." The other fires were at Kirkwood Rd, Dixon Dr and Benaraby Rd.
FRIDAY 4.45PM: The Queensland Fire and Emergency Service is currently fighting a small grass fire on Kirkwood Rd in Kirkwood.
QFES have two crews on the scene of the fire and are currently doing reconnaissance after their initial back burning has controlled the blaze.
There is a helicopter flying overhead and concerned locals watching on.