Authorities in Mexico have arrested the mayor of Michoacan’s principal port city for alleged Knights Templar ties, in an illustration of how embedded this criminal group is in the southwest Pacific state, and how hard it may be to eradicate their influence.

Arquimedes Oseguera, the mayor of Lazaro Cardenas, was detained on charges of kidnapping, extortion and drug ties. He has been accused of maintaining relations with Servando Gomez, alias “La Tuta,” the leader of the Knights Templar, reported Milenio.

According to security commissioner Alfredo Castillo, Oseguera’s arrest came as a result of investigations carried out by the Attorney General’s Office.

City treasurer Omar Alejandro Soto was also arrested for allegedly abetting the mayor, reported Animal Politico.

Oseguera is the second Michoacan mayor to be arrested in April, after the mayor of the town of Apatzingan was also recently detained for alleged organized crime ties and extortion.

His arrest occurs as authorities move to disarm the state’s vigilantes. The campaign began April 28 in three of the 27 municipalities where these groups operate, and 800 arms were registered on the first day, according to Milenio.

InSight Crime Analysis

Michoacan’s semi-legitimate vigilante groups emerged in 2013 with the stated mission of combatting the likes of extortion and kidnapping at the hands of the Knights Templar. Following a recent meeting with authorities, some leaders of these groups agreed to disarm by May 10 on the condition authorities take down this criminal structure in its entirety.

SEE ALSO: Coverage of Mexico Vigilantes

The Knights Templar have already been hit hard by the campaign against them. Both their top leader, Nazario Moreno Gonzalez, alias “El Chayo,” and second-in-command, Enrique Plancarte, alias “El Kike,” were recently killed, while federal officials claim they have closed in on La Tuta, the presumed heir to El Chayo.

Lazaro Cardenas is strategically important to the criminal group for the export of drugs and other illicit cargos, and entry of precursor chemicals, so it comes as little surprise the Knights had corrupted the city’s government to the highest level.

The vigilante demobilization process is already on shaky legs, with some leaders refusing to commit. While the mayor’s arrest shows authorities’ dedication to cleaning up Michoacan, it is also a reminder of how difficult this will be, and newly raises the question of how powerful self-defense groups with criminal potential will react if officials are unable to make good on their promises.