Following the arrest of drug lord Dionicio Loya Plancarte, leader of the Knights Templar criminal organisation, IBTimesUK looks into some of the most dangerous drug cartels in Mexico.
Los Zetas This criminal group takes its name from the tactical radio call sign for commanders in the Mexican army.
The cartel was founded in 1999 when commandos of the Mexican Army's elite forces deserted their ranks and started collaborating with the drug-trafficking Gulf Cartel.
In 2010, Los Zetas broke away from the Gulf Cartel to create their own gang which is considered by the US government to be the "most technologically advanced, sophisticated, and dangerous cartel operating in Mexico".
"The Zetas have obviously assumed the role of being the No. 1 organisation responsible for the majority of the homicides, the narcotic-related homicides, the beheadings, the kidnappings, the extortions that take place in Mexico," said US Drug Enforcement Agency's (DEA) chief for Mexico and Central America Ralph Reyes, after the cartel murdered a police chief, his wife and four children in Veracruz, Mexico.
Los Zetas were originally based on military lines, but the group has now been built into a business structure, with quarterly meetings, business ledgers, even votes on key assassinations, the DEA said.
Los Zetas also post videos on the internet showing the killing of people. In one clip, posted in 2013, a group of masked men behead four women who allegedly were tied to a rival gang: The Gulf Cartel.
The same treatment was observed for another woman, allegedly a member of the Gulf Cartel, who was decapitated by a man who then took her head and holds it as a trophy in front of the camera.
Los Zetas have carried out several other massacres on civilians and other gang members, such as the 2008 Morelia granade attack where granades killed at least eight people and left more than 100 injured.
During the 2010 First San Fernando Massacre, Los Zetas killed 72 immigrants. The following year, the Second San Fernando Massacre resulted in the death of 193 people.
The massacres and the public executions aim to strike fear into Los Zetas' opponents.
With eleven Mexican states under their control, Los Zetas are the cartel which control the most territory in Mexico.
The Knights Templar cartel is a Mexican criminal organisation created after the leader of the cartel La Familia Michochana split in 2010.
The cartel gets its name from the Templar Order of the Middle Ages which protected Jerusalem, and its hit men have commandments such as to protect the community and keep all activities secret, or the families will be killed.
According to journalist Ioan Grillo - who wrote the book El Narco: Inside Mexico's Criminal Insurgency, which documents how Mexican drug gangs have transformed into a criminal insurgency – the Knights Templar claim to be the protectors of Michoacan community.
When they first announced themselves , they displayed more than 40 narcomanteles, or drug-cartel banners, across the state with a message promising security. "Our commitment is to safeguard order, avoid robberies, kidnapping, extortion, and to shield the state from rival organisations," they said.
A week later, their first victim was hanged from an overpass with a note claiming that he was a kidnapper, according to Grillo.
"The massacres have rapidly given the Knights Templar a brutal reputation in an already barbaric conflict, in which drug cartels compete to prove who should be most feared," Grillo continued.
Members of The Knights Templar are treated as celebrities, one of its members stated in an interview.
"My days are marvellous because I am like an artist and everyone greets me, takes pictures with me [...] everyone wants to invite me somewhere and when I go out they offer me a bottle."
When asked whether it was worth joining the Knights Templar, the member answered: " Well yes it was. Now I have women I can choose from, I decide you: yes, and you: no. They give me gifts, gold, clothes and many things.
"I have seen how many others have to pay to have sex with them; I don't. [...]
I want to live, and the only way I want to die is like a warrior [...] I live in a cool way, I have money, women, cars and anything else I ask for."
Jalisco New Generation Cartel (CGNJ or Mata Zetas) Founded in 2009, when three men were found killed in an abandoned truck along with a message reading: "We are the new group Mata Zetas and we are against kidnapping and extortion, and we will fight them in all states for a cleaner Mexico."
After the death of drug lord Ignacio Coronel Villarreal in 2010, CGNJ declared war on all other Mexican cartels and stated its intention to take control of Guadalajara. However, by midsummer, the group appeared to have been reunited with its former partners, the Sinaloa cartel, Inter American Security Watch (IASW) reported.
CGNJ currently fights Los Zetas for control of the city of Guadalajara, Jalisco, and Veracruz.
CGNJ members are the perpetrators of many massacres, including the 2011 Veracruz massacre. Thirty five corpses were found in a track near a shopping mall in Veracruz, and a message was found along with the bodies: "No more extortions, no more killings of innocent people! Zetas in the state of Veracruz and politicians helping them.
"This is going to happen to you, or we can shoot you as we did to you guys before too. People of Veracruz, do not allow yourselves to be extorted; do not pay for protection; If you do it is because you want to. This is the only thing these people [Los Zetas] can do. [...] This territory has a new proprietor."
CGNJ was also responsible for 36 killings on 6 October 2011 and another 67 the following day.
In response to the multiple executions by the drug cartels, the federal government launched Operativo Veracruz Seguro (Operation Safe Veracruz), a military-led operation in the state of Veracruz.
"From the first day of my administration, the security agenda has been a priority in responding to the situation our nation is experiencing, and in Veracruz's case we are dealing with this in coordination with the federal government," Veracruz governor Javier Duarte de Ochoa said in a statement.
The Gulf Cartel (CDG) Active along the Gulf coast of Mexico, the CDG is probably the oldest criminal organisation, founded in 1930 by smuggler Juan Nepomuceno Guerra.
"The Gulf Cartel is responsible for the transportation of multi-ton quantities of cocaine, methamphetamine, heroin and marijuana from Colombia, Guatemala, Panama and Mexico to the United States, as well as the distribution of those narcotics within the United States," the DEA said.
The Gulf Cartel, together with Los Zetas, is the gang with the highest number of kidnappings in Mexico.
The Gulf Cartel is also responsible for money laundering, bribery, arms trafficking, solicitation and conspiracy to kidnap, attempted murder and interstate and foreign travel in aid of racketeering.
After the split with Los Zetas, the Gulf Cartel has suffered the loss of very important leaders and the infighting resulted in several deaths and arrests in Mexico and in the United States.
According to IASW the infighting has weakened the CDG, but the group seems to have maintained control of its primary plazas, or smuggling corridors, into the United States.
The Sinaloa Cartel (CDS, also known as Guzmán-Loera Organization, Pacific Cartel and Blood Alliance) is considered "the most powerful drug trafficking organization in the world" by the US Intelligence.
"The Sinaloa cartel has grown steadily more powerful since Guzman [Mexican drug lord at the head of CDS] escaped from a Mexican federal prison a decade ago by hiding in a laundry truck, even as successive Mexican governments - including that of Calderon - have faced accusations that they have not pursued the Sinaloa cartel as aggressively as other gangs," US intelligence said.
CDS controls over 17 Mexican states and it primary deals with the smuggling of Colombian cocaine, Mexican marijuana and methamphetamines.
The cartel moved in on the city of Juarez in 2008 and engaged in fighting with the Juarez cartel led by Vicente Carrillo Fuentes. The fighting prompted Mexican President Felipe Calderon to send thousands of army troops to the city. The violence resulted in the death of more than 5,000 people, making Juarez one of the world's deadliest cities.