Parts of the Mexican TV station Televisa have been damaged after attackers hurled a grenade at its office in Monterrey on Sunday.
According to the country's state-run Notimex agency, some "men in trucks" threw the device at the station's entrance at about 1.15am. No injuries have been reported although the blasts caused some damage to buildings.
Notimex reported that the attack followed a similar incident at Televisa's Matamoros office on Saturday night.
The two incidents came after last month's abduction of two Televisa journalists, along with two colleagues from other media, while they were covering corruption allegations at a prison in Durango state.
At least seven journalists have been killed in the country so far this year, and many more reporters are understood to have received threats from drug-gangs.
In the wake of increasing threats to journalists, the Inter-American Press Association has listed Mexico as Latin America's most dangerous country for journalists.