PHILADELPHIA (CBS) — Emergency responders were on the scene of a hazmat investigation in Old City early Wednesday morning.

The Philadelphia Fire Department’s hazmat team was called to the Wells Fargo building along the 400 block of Market Street shortly before 5 a.m. after a white powdery substance was found in the mailroom.

There were no injuries reported and the building was not evacuated.

Police had to close a section of 4th Street between Arch and Market streets as a result of the investigation.

The all clear was given shortly before 6:30 a.m.

Fire officials determined that the substance was not hazardous.