Fearless journalist, Javier Valdez Cardenas, who uncovered Mexico's drug cartels shot dead

Mexico is mourning the death of a journalist shot dead in broad daylight who was renowned for his fearless reports on the country's drug cartels.

On Monday (15 May) gunmen opened fire on the car of Javier Valdez Cardenas, 50, a correspondent for the newspaper La Jornada in his home town of Culiacan.

He had published his latest book in January called 'Mala Yerba', or 'Bad Grass' which described life under the narco gangs. In 2003, Valdez helped found a weekly publication called Riodoce, which reported on crime and corruption in the state.

He also wrote a number of books, including one called Miss Narco, about the lives of cartel leaders' wives, 'The Taken' about mass disappearances and another publication about children working for the gangs.

Some 30 journalists have been killed since 2012 and after the death of a reporter earlier this year, he told Fox News: "The effect of the violence is a kind of self-censorship. You have to know the rules – how the gangs or police or a local politician here or there will respond to a certain story – but those rules can change quickly."

He is the latest in a number of journalists in Mexico who have been killed for his work.

Valdez won the Committee to Protect Journalists' international press freedom award in 2011. Reporters without Borders says Mexico most dangerous country in the world for journalists.

A survey by the International Institute for Strategic Studies (IISS) has listed the drug war in Mexico as the second deadliest conflict in the world, with only the war in Syria being labelled worse.

Earlier in May, police captured Damaso Lopez, thought to be a senior figure in the feared Sinaloa Cartel and a former right hand man of Joaquin 'El Chapo' Guzman.