Posters threatening the life of Mexican singer Peso Pluma were put up in Tijuana on Tuesday, Mexican authorities said, as he was set to perform in the United States at the MTV Video Music Awards later in the evening.

Tijuana Mayor Montserrat Caballero said the prosecutor’s office is investigating the posters, which promised that the artist would be killed if he performed in the border town as scheduled in October.

One person has already been arrested, Caballero said.

“It is up to me to protect the citizens of Tijuana, and therefore in the next few days we will determine if the concert will take place or not,” the mayor said, adding that authorities were examining whether there were organized crime connections behind the threats.

Local media broadcast an image of one of the posters, signed with the initials “CJNG” — corresponding to the Jalisco Cartel–New Generation, a powerful drug gang.

In at least one of his songs, Peso Pluma shouts out a different gang, the Sinaloa cartel.

“Singers such as… Peso Pluma make apologies for crime, so there are certain groups that get upset,” Caballero said. “Unfortunately those who suffer the consequences are the citizens who want to attend their concerts.”

Peso Pluma, born Hassan Emilio Kabande Laija, has said in the past he has written songs “commissioned” by drug traffickers.

“Narcocorrido,” or drug ballad music, has proved controversial in Mexico, though the mayor said that she would not move to ban the genre’s concerts or broadcast over the radio because of its content.

The 24-year-old behind the hit “Ella Baila Sola” is scheduled to perform in Tijuana on 14 October.