SAN JUAN, Puerto Rico -- Authorities say a Puerto Rico policeman has killed three fellow officers following an argument at the station where they worked.
Spokeswoman Mayra Ayala told The Associated Press that the unidentified suspect was holding a female lieutenant, a male commander and a policewoman hostage before he shot them.
Ayala said authorities do not yet have information on a motive.
None of the victims have been identified. She said the suspect worked in the anti-drug division and has been arrested.
Authorities also evacuated the station to investigate threats of an explosive device.
The shooting occurred Monday morning at the police headquarters in Ponce, Puerto Rico's second largest city.
Puerto Rico's police force is the second largest in a U.S. jurisdiction.