Mexican marines have detained a man who identified himself as Ivan Velazquez Caballero, one of the top leaders of the notorious Los Zetas drug cartel.

In a brief statement, the Navy Secretariat said Velazquez Caballero, alias “Z-50,” “L-50” or “El Taliban,” was arrested Wednesday in the central state of San Luis Potosi and added that it would provide more information on Thursday.

The Zetas, a group founded by deserters from a U.S.-trained Mexican special forces unit, started out as the armed wing of the Gulf cartel, but those two criminal organizations had a falling out in 2010 and have since fought a brutal turf war in northeastern Mexico.