A woman was left devastated and in tears when an FBI Special Agent, who was not on duty at the time, shot and killed her dog during a walk.
The shooting occurred in Philadelphia's Rittenhouse Square just before 8 pm (1 am UK) on Monday night.
Witnesses and the dog's owner that were in the upscale square reported being horrified by the incident.
A local animal rights group identified the dog as Mia and called the shooting "unacceptable", while a p protest is planned outside the FBI headquarters in the city after the incident.
Police in Philadelphia are investigating the death of the dog.
Some neighbours reported being frightened after hearing the gunshot so close to their homes, while people who live nearby reported hearing a commotion and knew something was wrong.
Some neighbours, devastated over the dog's death, stood outside for hours trying to learn more about the incident.
One witness recounted hearing a bang and then seeing a woman shooting the dog.
Officers blocked off a small area on the block of Spruce Street where the incident occurred.
Witnesses reported watching the deceased dog's owner try to comfort her dog in its final moments.
The FBI said that the agent shot an aggressive dog and takes all shooting incidents involving agents and task force seriously.
According to Philadelphia police, the FBI agent was walking her dog in the area when another dog started attacking her dog.
The agent then shot and killed the other dog at 7.45pm. Monday, while no other injuries were reported during the incident.
Revolution Philadelphia, a local animal rights organization, released a statement condemning the incident and demanding that the agent be held accountable for her actions.
The protest outside the FBI headquarters is scheduled for 10 a.m. in response to the shooting.
