The discovery of 49 mutilated bodies dumped on a highway in northern Mexico on Sunday appears to be part of an increasingly gruesome war of intimidation among Mexican drug gangs. Here is a partial list of other notable incidents over the past 12 months.

— May 9: Police find 18 dismembered bodies close to Mexico's second-largest city, Guadalajara.

— May 5: The bodies of 23 people are found hanging from a bridge or decapitated and dumped near city hall in the border city of Nuevo Laredo.

— April 17: Police find the mutilated bodies of 14 men in a minivan abandoned in downtown Nuevo Laredo, along with a message from an undisclosed drug gang.

— April 12: The tortured and bound bodies of seven men are dumped in the Pacific port city of Lazaro Cardenas along with messages signed by allies of the Sinaloa drug cartel.

— March 18: Gunmen ambush and kill 12 police officers who had been sent to Guerrero state to search for the bodies of 10 people whose severed heads were found earlier.

— March 15: Officials identify a state lawmaker's body as one of 330 corpses found since April in mass graves in the northern state of Durango

— March 7: Authorities say they have found 16 bodies in three clandestine graves on the outskirts of Monterrey.

—Feb. 7: A suspected member of the Zetas drug cartel leads marines to mass graves at two ranches in the Gulf coast state of Veracruz where at least 15 bodies are unearthed.

— Nov. 24, 2011: The bound and gagged bodies of 26 young men are found in vans and a pickup truck on an expressway in the heart of Guadalajara. Officials say the Zetas are implicated.

— Nov. 23: The burned bodies of 17 people are found in two pickup trucks in the Sinaloa state capital of Culiacan.

— Oct. 15: Fight between gangs in Matamoros prison leaves 20 dead.

— Oct. 6: Alleged members of the New Generation gang allied with the Sinaloa cartel lead police to 32 bodies in the city of Veracruz.

— Oct. 2: The bullet-riddled, bound bodies of seven men are dumped at a downtown bus stop in the Pacific resort town of Zihuatanejo, along with a message from the Knights Templar group.

— Sept. 27: Five severed heads are found in front of a primary school in the resort of Acapulco.

— Sept. 20: The New Generation cartel dumps 35 bound, seminude, tortured bodies in front of terrified motorists at rush hour on a busy avenue in Veracruz.

—Aug. 25: Two dozen gunmen burst into a casino in Monterrey, douse it with gasoline and start a fire that kills 53 people.

—July 26: Police find 18 bodies in a clandestine grave near the city of Juarez in northern Mexico.

— July 8: At least 20 people are killed when gunmen open fire in a bar in Monterrey. Eleven bodies shot with high-powered rifles are found earlier in the day piled near a well in Valle de Chalco on the outskirts of Mexico City.

— June 7: Federal officials say that over several months they have found 193 corpses buried in the town of San Fernando in Tamaulipas state, most of them migrants kidnapped off buses and killed by the Zetas.

—May 25: Twenty-nine people wearing fake military uniforms are found heaped across a roadway and inside bullet-riddled vehicles after a battle between drug gangs in the Pacific coast state of Nayarit.

—May 14-15: Officials blame the Zetas for killing 27 workers at a cattle ranch in northern Guatemala.