Mexican marines arrive after an attack against the building of the Quintana Roo State Prosecution in Cancun earlier this year. A new report on armed conflicts included Mexico's drug cartel violence in its rankings.
State police officers patrol a highway between Ciudad Victoria and Matamoros, in northeast Mexico, in 2011. Mexico's drug and turf wars have descended on the once tourist friendly border town of Matamoros.
Mexico's Attorney General Jesus Murillo Karam addresses a news conference in Mexico City on Friday. He announced the arrest of three suspects in the brutal slaying of 43 students in the country's south.
Images from posters made by relatives show 10 of the 12 young people kidnapped in broad daylight from a bar in Mexico City on May 26. No one has claimed responsibility for the brazen abduction.