BOSTON (CBS) – The Moakley Federal Courthouse was evacuated Wednesday afternoon because of a bomb threat.

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WBZ-TV’s Karen Anderson was inside the courthouse when she was told to evacuate. Guards were reportedly calling the evacuation, “code red.”

Sources tell WBZ-TV a bomb threat was called into the courthouse.

A large crowd of media and civilians were gathered outside the courthouse after reports an arrest may have been made in connection with the Boston Marathon bombings.

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The State Police, FBI and Boston Police have since said no arrest has been made.

The crowd was moved about 100 yards away as police swept the courthouse.

The police presence includes Homeland Security, police vans, and Boston Police.

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Currently, only staff is allowed in the courthouse.