Facing growing threats from organized crime, Mexico’s top media companies on Thursday announced new guidelines designed to limit the use of grisly images of drug violence and pledged to work together to protect their reporters from harm.

About 700 news executives — including the television duopolies Televisa and TV Azteca, and top newspaper editors and commentators — also vowed “to avoid becoming unwitting tools for organized crime.”

Mexico’s news media offer a daily dose of photographs and videos of victims of drug violence, including beheadings, bodies hanging from bridges and scenes of alleged gang members — and even police — being tortured by masked sadists.

The journalists noted that the public displays are designed to terrorize the populace, intimidate authorities, and send chilling, coded threats to opposing drug organizations.

The nonbinding guidelines allow for continued use of bloody images. But in an apparent nod to complaints from President Felipe Calderon’s government that things are not as bad as the media report, the news groups pledged to “always present information in the right context and proportion” and to report “how it compares to what has happened, or is happening, in other regions and countries.”

Calderon often complains that homicide rates are higher in other places — such as Brazil or New Orleans — than in Mexico.

The journalists took note that Mexico’s democracy is threatened by unprecedented violence and that the country is one of the most dangerous in the world for reporters. In conflict zones in Mexico, many news outlets have stopped reporting daily killings, including street battles between government forces and alleged gangs.

“The places where it is really important to report the news, and the context, are the very places where the cartels have most of the power and will not allow the journalists to do their jobs. In fact, they will kill them for doing their jobs,” said Mike O’Connor, the Mexico representative for the Committee to Protect Journalists.

Not all journalists rallied around the pact. The weekly magazine Proceso did not sign, nor did the country’s standard-bearer, the Reforma newspaper. The popular CNN en Espanol host Carmen Aristegui expressed concern that the accord smacked of “almost patriotic journalism” and called for uniform behavior by what is often a free-wheeling press.

“The danger is that it could threaten freedom of expression and investigative journalism,” said Raul Benitez Manaut, a national security expert.

Said Javier Garza, editorial director at El Siglo in Torreon, who thought the pact could help vulnerable reporters: “But with violence as bad as it is in Mexico, the old mantra of ‘If it bleeds, it leads’ becomes dangerous for the media and harmful to the public.”