MEXICO CITY: A journalist was killed on Saturday in the northern Mexican state of Tamaulipas, adding to a wave of violence in one of the world´s most dangerous countries for media workers. Carlos Dominguez was murdered Saturday afternoon in the city of Nuevo Laredo, state officials said in a statement. The attorney general´s office has launched an investigation to determine the circumstances of the killing, including whether it was related to Dominguez´s work as a journalist, the state said. Dominguez was an independent journalist who wrote a political column. In one of his last publications, he lamented the growing political violence that has struck Mexico ahead of the presidential election in July.