SOUTH HAVEN, Mich. (AP) — An improvised explosive device that police say appeared to be made from modified commercial fireworks has damaged a home in southwestern Michigan.

The device was outside the home when it partially detonated about 4 a.m. Friday in South Haven. A window was blown out, but no injuries were reported.

South Haven police say investigators don’t know if people inside the home were targeted or if the incident was random.

Parts of the device that didn’t explode will be sent to the Michigan State Police Crime Lab to be analyzed.