Several vehicles were set ablaze early Wednesday at a repair shop in Brooklyn Park, days after two suspicious fires at playgrounds over the weekend in north Minneapolis and Brooklyn Park.

Authorities believe that the playground fires are related, but that Wednesday's fire was set by others.

About 10 vehicles at a transmission repair shop on the 6400 block of Lakeland Avenue were burning when firefighters arrived shortly before 4 a.m., Brooklyn Park Deputy Fire Chief Todd Seitz said. He said four of the vehicles were consumed by the flames.

The shop has video surveillance, but it does not record, Seitz said.

The first of the two playground fires occurred Saturday in north Minneapolis and has been ruled arson. The fire was set on the playground of the former Jordan Park Elementary School at Humboldt and 30th Avenues N., Assistant Fire Chief Cherie Penn said.

Jordan Park School closed in 2007. It is currently occupied by the district-operated Hmong International Academy. The building also will be home in the fall to Pierre Bottineau French Immersion, a new public elementary school.

On Sunday in Brooklyn Park, a fire deemed suspicious destroyed playground equipment at Park Brook Elementary School at 7400 Hampshire Av.

"We detected accelerants that were used," said Seitz, adding that he's confident the fire was set because "playground equipment just doesn't start on fire."

A juvenile suspect was arrested Monday, then released pending further investigation. Seitz said detectives are working to locate the juvenile.

Police Inspector Todd Milburn said Wednesday afternoon that adults are under suspicion for setting the vehicles ablaze. No arrests have been made in that case.

No buildings or people were harmed in any of the three fires.

Upon arriving at the Minneapolis blaze Saturday, firefighters found fire consuming the plastic equipment and heavy smoke, Penn said. Shredded tire mulch on the ground around the equipment "contributed to the large volume of smoke," she said.

By the time the flames were extinguished, two-thirds of the equipment had melted, Penn said.

Anyone with information about the fire is asked to call the arson hot line at 1-800-723-2020.

Paul Walsh • 612-673-4482