The Mexican navy says top Zetas drug cartel leader Heriberto Lazcano has apparently been killed in a firefight with marines in the northern border state of Coahuila,

The navy says there is strong evidence the body of one of two men killed in the shootout is Lazcano, who is also known as "El Lazca."

However, the navy says forensics tests will have to be carried out to confirm the identification of the body.