(CNN) -- A photographer for El Diario newspaper in Ciudad Juarez, Mexico, was gunned down Thursday, the paper said on its website. A second photographer was injured in the shooting.
Luis Carlos Santiago, 21, was declared dead at the scene. He and his co-worker were inside a silver Nissan sedan in the parking lot of a shopping mall, the newspaper said. Santiago was in the driver's seat.
Unidentified gunmen followed the pair to the Rio Grande Mall, which is located near the newspaper offices, a source with knowledge of the investigation told CNN.
The injured journalist, who was an intern, was hospitalized in stable condition, the official said.
Ciudad Juarez is one of the deadliest cities in Mexico, and the country is one of the most dangerous for journalists. The violence stems from turf wars between rival cartels and battles between the cartels and the Mexican authorities.
The source said it was too early to know whether Thursday's killing was related to the drug violence.
The gunmen used 9mm handguns, the official said.
Santiago is the ninth journalist killed in Mexico this year, according to the Committee to Protect Journalists.
Drug cartels pressure journalists and editors in Mexico to avoid reporting on them and to print unflattering stories about rival drug cartels. The result has been increasing self-censorship from many media outlets throughout the country.
Press freedom organizations say Mexico does not do enough to investigate the killing of journalists.
A recent CPJ report found "systemic failures that if left unaddressed will further erode freedom of expression and the rule of law. Vital national and international interests are at stake."