Mexican federal agents have detained an alleged leader of a local drug gang in the southern state of Guerrero along with the mayor of a town where authorities believe 43 missing students were killed and incinerated.

A federal official who was not authorized to be quoted by name said Friday that suspect Adan Zenen Casarrubias allegedly leads the Guerreros Unidos gang.

The official said the mayor of the small town of Cocula was detained with Casarrubias. Mayor Erick Ulises Ramirez recently took office, and was not mayor when 43 students were allegedly killed in Cocula in late September 2014.

Police in the nearby city of Iguala allegedly detained the students and turned them over to Guerreros Unidos gunmen. It was unclear if the Thursday detentions were related to that case.