Mexican presidential candidate Claudia Sheinbaum greets supporters upon her arrival to her opening campaign rally at the Zócalo plaza in Mexico City, on March 1.

Caption

Mexican presidential candidate Claudia Sheinbaum greets supporters upon her arrival to her opening campaign rally at the Zócalo plaza in Mexico City, on March 1. / AP

MEXICO CITY — Mexico is a country in the midst of a deadly turf war between rival cartels and government security forces.

One of the symbols of that turf war are checkpoints. Sometimes they are run by municipal police or the military, other times they are run by mysterious masked men. They usually ask you a few questions, take a few notes and you're off to your destination.

On Sunday, Claudia Sheinbaum, the leading presidential candidate in Mexico, was stopped at one of those roadblocks by a group of men covering their faces with ski masks.

In video of the encounter, Sheinbaum — a front-runner in the polls — looks on as one man tells her: "When you get to power, remember the mountains, remember the poor people. That's all we have to say. We are not against the government; we are here so you see the disaster that is Comalapa."

Comalapa is a small town in Chiapas, a state in southern Mexico that borders Guatemala and used to be relatively peaceful. But as Mexico's two biggest organized crime groups — the Sinaloa cartel and the Jalisco New Generation cartel — have tried to extend into new territory, their fighting has brought chaos to Chiapas.

So, who were these mysterious people in masks? Latinus, an online news site that was there when it happened, says they are "autodefensas," armed civilians who patrol their communities.

In comments to the press, Sheinbaum did not clear up anything. Instead, she intimated this was staged by her monied opponents.

"They said they were villagers, that they weren't hoity-toities. It's all very strange," Sheinbaum said.

One reporter points out that some of the villagers told them the masked men were in fact members of the Sinaloa cartel. "I don't believe it," says Sheinbaum.

In his morning briefing, President Andrés Manuel López Obrador downplayed the incident.

"This is propaganda," López Obrador said, adding that the masked people had very likely been planted by political enemies. The incident will be investigated, the president said, but he said it was not "very serious."

But the encounter at the checkpoint reveals the tenuous security situation in the country. As the cartels fight for territory and power, they have turned parts of Mexico into some of the most violent places on Earth. And the violence has not spared politicians. This political season alone, 17 candidates have been assassinated. Two mayoral candidates were found dead just last Friday. So far, according to The Associated Press, the government has offered police protection to 250 candidates.

Tiziano Breda, who studies political violence in Mexico at the Armed Conflict Location and Event Data Project, says it's hard to see an incident like this as anything but a threat to Mexico's leading presidential candidate.

The government of López Obrador, he said, has customarily dismissed incidents like this, because if it admits that organized crime or some other group is trying to intimidate Mexico's leading presidential candidate in such a crass way, it would be a tacit acknowledgment that "things are really out of control."

"It means that the government hasn't been able to rein in organized crime and has actually somehow allowed it to grow even further to this level," he said.

Sheinbaum, whose wide lead in opinion polls puts her on track to become Mexico's first woman president in the June 2 elections, campaigns without much security.

Her campaign has mostly skirted the violence afflicting Mexico and focused on the social programs that have made the current president hugely popular.

Her opponent, Xóchitl Gálvez, has focused on security. Her campaign slogan is: "For a Mexico without fear."