The Sarnia Fire and Rescue Service is planning to do a safety campaign at Rainbow Park after recent fires.
Fire Prevention Officer Roel Bus said two fires were reported at the homeless encampment, set up in the park off Christina Street, within the past week.
While a candle was believed to have sparked the first fire on Friday morning, Bus said the cause of a second fire on Sunday morning is undetermined.
"Because everything is so flammable and combustible, it's pretty well all gone by the time we get there and it's going to be hard to know what actually caused [the fire] unless we hear from people what actually happened," said Bus.
So far no injuries have been reported, and Bus hopes to keep it that way.
"We have reached out to other agencies to coordinate a safety campaign which includes fire safety. It's mostly regarding candles and campfires. We've also seen barbecues in close proximity to tents," he said.
Bus said open flames are always a risk in these scenarios.
"The tents are all in close proximity, so obviously that's a concern to us. Any open flame fires are a threat to each and all of the tents, and open burning is not permitted, it's still a public park," said Bus.
Those encamped in the public space were notified in late June that health and safety measures, including temporary washrooms, would be added to address other concerns.
The measures also included temporary fencing, lighting, and security during daylight hours.
-With files from Natalia Vega