In the violent southern Mexico town of Chilapa, just being named Sanchez, Nava or Carreto can lead to trouble.

Several men with those last names were among 10 to 14 people who vanished from the Guerrero state city when a 300-strong armed group occupied Chilapa for five days in May.

Relatives of the missing fear they were kidnapped because they share the same names as a notorious drug lord and a former police chief in a region where crime and politics often intersect.

The armed group, which described itself as one of the "community police" forces that are common in Guerrero, entered Chilapa on May 9, disarmed the municipal police and blocked the town's entrances.

They left on May 14 after an agreement with federal authorities.

Residents say the armed group was infiltrated by Los Ardillos, a local drug gang which is fighting for Chilapa against a rival criminal group known as Los Rojos.

The armed group has rejected kidnapping and criminal links accusations.

During the occupation, at least 14 men, most between the ages of 15 and 25, vanished without a trace, according to a list their relatives provided to AFP.

Authorities say they are investigating the alleged kidnapping of 10 people in the town of 120,000 people, which lies on a strategic route for heroin traffickers who grow opium poppies in the surrounding mountains.

- Selling cattle and pizza -

Armed civilians stand guard at the entrance to Chilapa in Guerrero State, southern Mexico on May 10, 2015 Pedro Pardo, AFP/File

Witnesses say that the armed group went around town with rifles and machetes, shouting "Give up 'El Chaparro!' and we'll go away!"

"El Chapparo" is the nickname of reputed Los Rojos leader Zenen Sanchez Nava.

One man had just left his job at a pizzeria when he disappeared, others had come to Chilapa to sell cattle.

Alexandro Nava Reyes, a 21-year-old truck driver, told his parents on May 10 that he was going to visit his girlfriend "but he never came back," his sister Melissa said.

Four other young men whose parents have either Sanchez or Nava in their last names disappeared.

"Being Nava or Sanchez is extremely dangerous in Chilapa," said Jose Diaz, a teacher and spokesman for relatives of the missing.

Jose Apolonio Villanueva, a farmer and leader of the armed group, said the goal of their "visit" to Chilapa was to speak with the mayor because "many people have been lost in our communities" as well.

While they never saw the mayor, Apolonio's group was able to negotiate the resignation of the town's police chief.

Another former Chilapa police chief, Silvestre Carreto González, stepped down in July last year.

The missing include three brothers, Miguel, 23, Juan, 20 and Victor, 15, whose last names are Carreto Cuevas and were last seen when they came to Chilapa to sell a cow.

Two other relatives, Crispino Carreto Gonzalez and his son Samuel, also disappeared between May 9 and 14.

Guerrero State police patrol in the back of a pick-up truck in the city of Chilapa, in the southern Mexican, on the eve of midterm elections on June 6, 2015 Pedro Pardo, AFP/File

Residents believe the disappearances of the Carretos was some sort of vengeance against the former police chief in a region where authorities are often accused of colluding with criminals.

A week after the armed group left Chilapa, three bodies were found near the town with their facial skin peeled off. But authorities say the victims were men who had disappeared before the May 9-14 occupation.

- Drugs and politics -

Esther, another sister of Alexandro Nava, said the latest unrest in Chilapa began before June 7 midterm elections.

"It all started because of the elections," she said, recalling how masked men tried to place next to her house a banner demanding that people support a political party.

A day before the legislative, municipal and gubernatorial vote, relatives of the missing held a protest against what they termed "narco-elections."

Jesus Parra Garcia of the ruling Institutional Revolutionary Party (PRI) won the mayoral race. He replaced another PRI candidate who was shot dead on May 1.

"It doesn't matter who wins. If they don't arrest Los Ardillos and Los Rojos, the situation will stay the same," said Diaz, the spokesman for the relatives.

"The election only decides if the mayor is Rojo or Ardillo," added Diaz, who said two of his brothers were killed by Los Ardillos last year.

Chilapa is near Ayotzinapa, the location of a teacher training college still reeling from the September disappearance of 43 students who, according to authorities, were attacked by police in the city of Iguala under the mayor's orders.

Officials say Iguala's officers handed the students to the Guerreros Unidos drug gang, which has been battling Los Rojos and is accused of killing the 43 young men.