The FBI is investigating after St. Paul police reported finding remnants of an explosive device near an unoccupied squad car late Wednesday.

An officer stationed in the old Sears parking lot near the Minnesota State Capitol heard an explosion just before midnight and saw smoke billowing from across the street. She followed the smoke to a public housing complex at 280 Ravoux St., just off Interstate 94, where she found debris from an apparent incendiary device.

No one was injured in the blast.

Preliminary information indicates the "device detonated near or possibly under the squad car," said police spokesman Sgt. Mike Ernster. The department's bomb squad responded to the scene, where they are working with federal investigators to determine what type of device it was and whether it was intentionally set.

The marked police cruiser is associated with the St. Paul Police Department's community outreach program, which works with several public housing properties in the area.

As of Friday, no arrests had been made.

Liz Sawyer • 612-673-4648