Photojournalist shot dead in Mexican border city

A photojournalist was shot dead Monday in Mexico's crime-plagued city of Tijuana bordering the United States, authorities said -- the latest such murder in one of the world's deadliest countries for reporters.

Margarito Martinez, 49, was attacked with a firearm and his body found near his home, the security secretariat in the northwestern state of Baja California said in a statement.

Martinez, who specialised in news related to the police, had a gunshot wound to the head, according to prosecutors.

"Freedom of expression, in all its forms, is a fundamental right of citizens," the Baja California Attorney General's Office said in a statement.

Martinez, who worked for media including the weekly Zeta of Tijuana, had received threats from people linked to organised crime, according to a media rights group, Yo si soy periodista (I am a journalist).

Authorities were also urged to investigate an attack that led to the death of another journalist and social media activist, Jose Luis Gamboa, in the city of Xalapa in the eastern state of Veracruz.

Gamboa was taken to hospital on January 10 after he was stabbed and left lying on the street, but his body was not identified until Friday.

It was unclear if the killing was related to his work.

Gamboa is not known to have been threatened, according to the State Commission for the Attention and Protection of Journalists.

Even so, media rights watchdog Reporters without Borders (RSF) urged prosecutors to thoroughly investigate the killing.

"Gamboa had denounced and strongly criticised local authorities for their relationship with organised crime," it tweeted.