The mayor of a municipality in the notoriously violent Tierra Caliente region of Guerrero was among 20 people killed in an armed attack on Wednesday.

Guerrero authorities reported Wednesday that 18 people were killed and two others were wounded in an attack on the San Miguel Totolapan city hall, but federal security official Ricardo Mejía said Thursday that the death toll had risen to 20.

Gunmen affiliated with Los Tequileros – a crime gang allegedly linked to the Jalisco New Generation Cartel – are believed to be responsible for the massacre in the small town, part of a region where violence is common and narcos exert significant influence over local politics.

San Miguel Totolapan Mayor Conrado Mendoza Almeda, his father Juan Mendoza Acosta – a former mayor of the same municipality, and other local officials, including police officers, were among those murdered in the attack. The Democratic Revolution Party mayor’s grandfather and brother-in-law – a United States citizen identified as Gustavo Salazar – were also killed.

Some reports said that Mendoza Acosta – who allegedly colluded with Los Tequileros while mayor – was killed at his home in San Miguel Totolapan rather than at the local government headquarters. Mendoza Almeda was presiding over a meeting when the assailants stormed the town hall and opened fire.

The army, police and the National Guard attended the scene of the crime but no arrests were reported. Guerrero Attorney General Sandra Luz Valdovinos said in a television interview that their arrival was delayed by blockades allegedly set up by the crime group that committed the attack. Her office said that 10 victims had been identified and released a list of their names.

Mejía, a deputy security minister, told President López Obrador’s regular news conference that the massacre occurred “in the context of a criminal dispute” between Los Tequileros and La Familia Michoacana drug cartel.

“A group known as Los Tequileros ruled in that region during a period of time; it was a group mainly dedicated to the trafficking of opium poppies,” he said.

Mendoza Alameda is the 18th mayor to be murdered since López Obrador took office in December 2018, according to Etellekt Consultores, which tracks political violence.

In a separate incident, Morelos state Deputy Gabriela Marín was also shot and killed on Wednesday. The deputy, who was gunned down in state capital Cuernavaca, is the eighth state lawmaker to be killed since the president was sworn in almost four years ago.

With reports from Aristegui Noticias, AFP and Político