Puerto Rican cop guns down three fellow officers at police headquarters
Gun and blood at crime scene (Shutterstock.com)

A police officer shot and killed three of his fellow officers Monday morning at a Puerto Rican police headquarters.

The officer, whose name was not released, was arrested after killing a police commander, a lieutenant and another officer in Ponce, reported CNN.

It's not clear why the officer shot his colleagues.

"There are no words to describe this tragedy where three colleagues have lost their lives," said Col. Juan Rodriguez Davila, deputy superintendent of Puerto Rico Police.