MEXICO CITY — More than three dozen Mexican media organizations announced Monday that they are joining forces to try to combat a wave of journalist killings in the country, including at least nine this year.

Signed by 39 print, radio and television outlets, the initiative calls for a working group to outline objectives and establish channels of communication with national and international human rights groups. The organizations also agreed to launch an awareness campaign aimed at Mexican society.

“The battle against impunity will only be effective if we have on our side a society that understands that with each killing of a journalist, they lose hold of their right to know, to participate, their very essence as citizens,” the agreement’s text said.

The announcement coincided with a visit to Mexico by the special investigators on freedom of expression for the United Nations and the Inter-American Commission on Human Rights, David Kaye and Edison Lanza.

In a statement, they called journalist killings “a crisis in Mexico for over a decade” and urged the government to devote the necessary resources to support measures of protection and transparency.

“Mexico has already taken a laudable step by creating these institutions; now it should give them the tools to be effective,” Kaye and Lanza said.