Another journalist was slain in Mexico on Monday, a government official has confirmed.

The government official in the northern state of Sinaloa says veteran reporter and writer Javier Valdez was killed near the offices of his newspaper, Rio Doce, in the state capital of Culiacan.

Rio Doce confirmed the news of Valdez's killing on its webpage.

Valdez, 54, also worked as a correspondent for the national newspaper La Jornada. He specialized in covering drug trafficking and published several books on the topic.

"The better you do journalism and the more passionate you get, the lonelier you get. One of your contacts [for example], someone who used to be be sympathetic to your work, gets damaged by one of your stories and he withdraws," Valdez said to La Jornada recently.

Valdez's most recent book, "Narcoperiodismo" (Narco-journalism), addresses the challenges of practicing journalism in a region ruled by drug-traffickers. It was publsihed in October.

So far this year five journalists have been murdered in Mexico, one of the world's most dangerous countries for media workers.

Last month, a newspaper in the border city of Juarez closed due to the climate of insecurity and impunity for killings of journalists.

The AP contributed to this report.