Police findings point to a link between a local Salvadoran gang, based in the center of the country east of San Salvador, and the notorious Mexico-based Zetas drug gang.

El Salvador’s civil police said that gang members linked to the Mexican cartel were mainly active in the municipalities of Soyapango, llopango and San Martin, in the San Salvador province.

The police estimated the gang’s membership to be around 250, with at least 110 of these being held in prisons across the country.

Authorities linked the group to the murder of 14 people, including two students from the National Public Security Academy and well as rival gang members. Last week 35 members of the gang were arrested in connection to these killings.

The Zetas have been increasing their zone of influence south from Mexico, moving into countries like Guatemala and El Salvador. In June Salvadoran President Mauricio Funes acknowledged the growth of the Zetas in his country, while the military has warned that weapons stolen from the country’s arsenals have ended up in the hands of the Mexican group.

El Salvador remains one of the most violent countries in the world, estimated to have some 20,000 gang members.