Mexican journalist Jorge Armenta was killed Saturday in Ciudad Obregon in the country's north, making him the third journalist slain in Mexico so far this year, authorities said.

"An armed attack has been confirmed that took the life of Jorge Armenta," director of digital media outlet Medios Obson, the regional prosecutor's office said on Twitter. A municipal police officer was also killed and a second officer was wounded, it added, without providing further details on the attack.

Armenta had received threats and was under government protection, said the media watchdog group Reporters Without Borders (RSF). RSF, which said Armenta was the third journalist killed this year, is investigating the type of protection he had. Local authorities said they were also probing the killing.