CAMBRIDGE (CBS) – A small fire set off a hazardous materials scare late Saturday night, and investigators are still exploring the cause.

The fire started in a refrigeration unit at Cambridge Biomedical, a building owned by Harvard University.

Soldiers Field Road was partially blocked off, and the area contained signs warning of hazardous materials.

An environmental team was brought in and determined the scene was safe before re-opening the road.

The fire is still under investigation.