Arson is suspected in four instances of school district playgrounds in north Minneapolis being set on fire since mid-June, causing about $200,000 in total damage and rendering the play areas unusable for students returning to classes, authorities said.

While the targets are similar and are all on the North Side, police and fire officials said Tuesday in a joint statement that “there is nothing to indicate that any of the fires are related.”

Among the factors leading to that conclusion is that the “locations are far apart,” said Police Sgt. William Palmer.

Authorities report no injuries, and no arrests have been made.

The most recent fire occurred midafternoon Sunday at Jordan Park School (Hmong International Academy and Pierre Bottineau French Immersion), 1501 30th Av. N., according to the Fire Department.

The torching created heavy black smoke and flames from the rubber mulch on the ground, fire officials added. The smoke set off the school alarm. Damage was estimated at $30,000, said district spokeswoman Larissa Chinwah.

The first and most extensive blaze occurred June 13 at Lucy Craft Laney at Cleveland Park Community School, 3333 Penn Av. N. Along with the playground, exterior masonry, windows and doors were damaged. Chinwah said the damage was estimated at $125,000.

Next came two fires set at the Mona Moede early childhood and Pre-K school near 24th and Girard Avenues N., on Aug. 5 and Aug. 21. Damage estimates were $30,000 for the first blaze and $15,000 for the second, Chinwah added.

Anyone with information about any of the fires is asked to call the fire department’s arson hot line at 612-673-3070 or 1-800-723-2020. A reward of $2,500 is being offered.