Mexico\'s navy said Friday it had caught a member of the Zetas drug gang who allegedly participated in the brutal torture and killing of four Marines in the eastern state of Veracruz last month. Marcos Jesus Hernandez Rodriguez was the \"suspected head of a group of hitmen\" for the Zetas and is blamed for the torture and death of at least four members of the Marines, a statement said. The Marines were reported missing on April 18 near the state capital of Xalapa, where they had been taking part in a vehicle repair workshop. They had not been involved in a federal crackdown on drug traffickers in the region, the statement said. Hernandez Rodriguez, also under investigation in connection with seven other murders, was detained on Wednesday. Veracruz is in the grip of a turf battle between the Zetas drug gang -- set up by ex-soldiers-turned-hitmen in the 1990s -- and allies of the powerful Sinaloa cartel of billionaire fugitive Joaquin \"El Chapo\" Guzman. More than 50,000 people have been killed in drug-related violence since President Felipe Calderon launched an all-out war against the nation\'s drug gangs on taking office in December 2006. The government\'s official count of more than 47,000 dead has not been updated since September.