Three suspicious fires in a pine forest during the past week all had the potential for disaster, Alexandra's chief fire officer Russell Anderson said.
"I'm concerned that someone is going to get hurt.
"If it's not the person lighting the fires, it'll be a member of the public," he said.
Police and fire service staff were investigating the fires.
All followed a similar pattern and all were in the Department of Conservation reserve near the Molyneux Estate housing subdivision, on the outskirts of the town.
"I suspect that a young person is involved.
"The fires have happened at 8am, at 3.15pm and last Friday night.
"Someone must know something or have suspicions about someone coming home smelling of smoke," Mr Anderson said.
"We've been very lucky that each fire has been spotted quickly by the public and they've been quickly contained and extinguished, but there is the potential for disaster, so I'm very concerned about this trend."
Anyone with information is asked to contact the police.
There is a total fire ban in place in Central Otago.
