(CNN) A police officer in Paris died after her colleague shot her in the head, in what police union leader Christophe Crepin called "a tragedy due to a mistake in handling a loaded firearm."

According to French newspaper Le Parisien, the victim and the suspect were playing with their guns Sunday when the incident occurred. As yet, neither has been publicly named.

The victim was shot in the central offices of the Paris judicial police in the city's 17th arrondissement, where she and her male colleague were guarding the building. The newspaper reported that she was 27 and her colleague is 28 years old.

Crepin told CNN that the suspect has been suspended and taken into custody. The Paris prosecutor's office has launched an involuntary homicide investigation.

Le Parisien reports that the colleagues were "playing at drawing their weapon" when the officer was fatally shot, and that two other officers were present.

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