Detective Sergeant Kate Bartlett, of Balclutha, said police were asking residents about two arsons on a Water St property on January 2 and January 22, two suspicious fires in a forestry block on February 25, and a suspected arson on a Christchurch St property last Saturday.
"We are not saying the fires are linked," Det Sgt Bartlett said.
"We are crossing off all the inquiries. We are inquiring on anyone who may have seen or heard something but not contacted police."
Police set up a caravan base at Victoria Park in Kaitangata to make a "targeted effort at getting round local witnesses", who were already coming forward with information.
Balclutha police were joined by a tactical team from Dunedin yesterday, and Balclutha police will continue making inquiries today.
The response from the public had so far been positive, Det Sgt Bartlett said.
Local business owners Derek and Marie Calver said they were pleased to see the police in town.
"It's good the police are out here, trying to get who it is," Mrs Calver said.
"Being business people, we do have a great concern over it."
Mr Calver said several people in Kaitangata had been renovating houses recently.
"People are starting to take a bit of pride in their homes, and the last thing you want is an arsonist running around."
