Two offices belonging to Mexico’s largest media organization, Televisa, were attacked with explosives at the weekend, a week after thousands of journalists marched silently through Mexico City, the capital, to protest against the violence, intimidation and harassment journalists face in the Central American country.

The first of the two attacks happened in the northern border town of Matamoros, Tamaulipas state, at 9 pm on Saturday, 14 August when unidentified individuals threw a grenade from a moving vehicle which hit the buildings of Canal 7, Televisa’s local channel in the city.   No one was injured during the attack but damage was sustained to a storage area.

The second attacked occurred just hours later, at 1.30 am on Sunday, 15 August, when Televisa’s studios in Monterrey were targeted. Contrary to early local reports, Televisa later confirmed that no one had been injured but nearby vehicles, including one belonging to the station, and building windows were damaged.  Monterrey – Mexico’s richest city and industrial capital – has seen a surge in drug-related crime and violence since one of Mexico’s most violent drug gangs extended its operations to the city.

Veiled threats from a supposed drug trafficker had appeared on the website of the Monterrey-based daily newspaper El Norte ahead of the second attack, according to local press freedom organization CEPET (Center for Journalism and Public Ethics).

Two journalists from Televisa were among four journalists kidnapped in the northern state of Durango in July. They were freed a few days later. During their kidnapping, the journalists’ TV stations were forced to broadcast messages from the kidnappers implicating a rival gang in a corruption scandal. Televisa cancelled the popular news show “Starting Point” in protest at the kidnappings. The screen went blank for the duration of the show.

Televisa had faced similar attacks in recent months with the offices in Monterrey hit on 6 January last year and Televisa’s Canal 57 station in Nuevo Laredo, also in Tamaulipas state, attacked on 30 July this year.

Following the escalation of violence and the harassment journalists have faced during the government’s attempts to crackdown on the powerful drug cartels, some thousand journalists participated in the “For your right to know and my right to inform: No more attacks on journalists” march in the country’s capital of Mexico City and other major cities, on 7 August.

Journalists carried banners with slogans such as “Not one more!” and “No journalists, no information,” as well as carrying photographs of murdered colleagues.

Speaking to Spanish-language news agency Efe, organiser and co-editor of Mexico City-based daily Excelsior Elia Baltazar explained the reason behind the silent protest: “It’s a march in which we Mexican journalists renounced the spoken word, because the spoken word is at risk,” the journalist said.

IPI Press Freedom Manager Anthony Mills said: “Mexican journalists continue to operate under the sustained threat of extreme violence. This has a direct impact on their ability to gather and transmit information that is in the public interest. The Mexican authorities must do all they can to confront this brutal effort to silence the media.”

Since the International Press Institute’s Death Watch began in 1997, at least 59 journalists have been killed because of their work in Mexico, making Mexico the fourth most dangerous country in the world for journalists in the past decade and the most dangerous thus far in 2010.