Mexico’s navy announced Monday the arrest of 35 police officers in the Gulf coast state of Veracruz on allegations they were working for the Los Zetas drug cartel.

Marines detained 16 of the suspects at the airport in San Luis Potosi, capital of the likenamed neighboring state, while the rest were picked up in Xalapa, Veracruz’s capital.

All of those arrested are members of the Veracruz state police, the navy said in a statement.