The Nanaimo RCMP and the city’s Fire Department are warning downtown businesses to be careful with what they leave out for collection or recycling.

In the past three months, there have been more than 20 suspicious fires.

Many were minor dumpster fires, but one on Cliff Street on June 4th had the potential to cause significant damage.

The Nanaimo RCMP says many of the fires were started in cardboard and other flammable materials.

The RCMP has posted a map of the fire locations and says several persons of interested have been identified.

Because firefighters are often the first to arrive at a fire so they are working with the RCMP to preserve evidence and help identify potential witnesses and suspects.

Arsonists may check out a location first and homeowners or businesses that see suspicious activity should report it to the police.

Nanaimo Fire Chief Tim Doyle says combustible materials left outside businesses overnight and unsecured dumpsters are a big concern.

“The biggest concern we have is combustible materials stored outside businesses overnight. Most are added to dumpsters that are not secured. These need to be locked and the waster material disposed of or removed from the site daily.”

Doyle says cardboard, wooden pallets, used cooking oil, containers, Styrofoam or packing materials, and other flammable materials need to be removed.

He also says the areas around buildings, alcoves, and alleyways should be kept clean.

The Nanaimo RCMP is asking anyone with information that may their investigations to contact their non-emergency line at 250-754-2345.