Brutal violence escalates in Mexico drug wars

>> much. now to mexico and the escalating war between that country's drug cartels . authorities are now struggling to identify 49 bodies dumped on the side of a highway. the latest in a series of brutal massacres. nbc's mark potter is in mexico city . and mark, as i say good morning we want to warn our viewers the details of this story are very disturbing.

>> that's exactly right. good morning to you, matt. for years the mexican drug war has been defined by its horrific brutalty, which in some areas appears to be getting even worse. the latest atrocity occurred near the city of monterrey, and as you just said, some of the images and details coming up here are indeed disturbing. the mutilated bodies were found along a busy highway near monterrey, mexico , about 75 miles south of the u.s. border. the victims, 43 men, and 6 women, had their heads, hands and feet cut off. and are believed by mexican and u.s. authorities to have been killed by members of an extremely violent drug cartel .

>> los vetas want to show they're the meanest, most sadistic, most cruel criminal organization in the americas. and they do that by committing absolutely unspeakable acts of brutality.

>> reporter: sources say the victims may have been members of a rival cartel. a war over smuggling routes between los zetas and the sinaloa cartel has led to extreme violence .

>> the fight between them is for domination of offloading points, transit points, and especially crossover points on the border.

>> reporter: in acapulco, mexico , cartel violence has turned a major international tourist destination into another front in the drug war . with more than 900 people killed there last year. as authorities try to gain control over organized crime groups. last week near guadalajara authorities found 18 beheaded bodies in two vehicles. nine other victims were hanged from a bridge just south of the texas border. in the last six years an estimated 50,000 people have died in mexico 's drug war . former mexican foreign minister is now an nbc news analyst.

>> a lot of people hoped that this would diminish that little by little the violence would start to descend, that little by little there would be fewer killings, less gory killings. i think what we've seen the last ten days or two weeks shows that that's just not going to happen.

>> the mexican government continues to attack and arrest cartel leaders. the next step in that war, is now a major issue in mexico 's presidential campaign, leading to elections this summer. now u.s. officials say they still strongly support the mexican government in its war against the cartels, as those cartels continue to lash out at each other, and at anyone else standing in their way.