PHILADELPHIA (AP) – A fire official says the second floor of the federal court building in Philadelphia has been evacuated after authorities found a letter containing a threat about anthrax.

Executive Fire Chief Richard Davison says crews responded to the federal court building in the city’s historic district around 9:25 a.m. Wednesday. He says people have been evacuated from the second floor, but people on other floors remain in the building.

Davison says a letter was found, but he did not immediately know if any substance was found.

A spokeswoman for the Philadelphia Police Department says officers are also responding to the scene, but she did not immediately have additional information on what prompted the response.