These acts of violence highlight the "growing insecurity in general" and "exceptional particular vulnerability" of the press in Mexico, said in a press conference OHCHR spokesperson Rupert Colville.Last Saturday, the maimed and decapitated body of Mary Elizabeth Macias, 39, managing editor of the newspaper Primera Hora, appeared beheaded in the city of Nuevo Laredo (border with the U.S.), with a message saying she was killed for reporting on organized crime activities in social networks.Mexico is the most dangerous country in the Americas for journalists, according to a UN report published in June.Since early this year, five journalists were murdered in Mexico, according to the Inter-American Commission on Human Rights, headquartered in Washington."The magnitude and nature of these murders are horrific," said Rupert Colville, noting that "women are killed everywhere.""We understand the challenge facing the Mexican government in its fight against increasing violence," he said."However, we are also extremely concerned about the immunity prevails over these killings and committed many similar crimes in recent years," insisted the spokesman."We ask the Mexican authorities to open immediately full and impartial investigations into those events," he said.