8 October 2012 Last updated at 16:17 ET

Mexico navy arrests suspect in 2010 Zetas killings

Martinez is accused of ordering the murder of hundreds of migrants

The Mexican Navy has arrested a man it says was behind the 2010 murder of 72 migrants in northern Tamaulipas state.

The Central and South American migrants were found buried in a mass grave at a ranch near the town of San Fernando.

Salvador Alfonso Martinez, 31, is accused of being a regional leader of the violent Zetas drug cartel.

The authorities believe the migrants were kidnapped to swell the ranks of the cartel, and were killed when they refused to work for the Zetas.

The Navy said it had captured Martinez, also known as Commander Squirrel, after a shoot-out in Nuevo Laredo near the US-Mexico border on Saturday.

Navy spokesman Jose Luis Vergara said Martinez led the Zetas drug cartel in the northern states of Tamaulipas, Nuevo Leon, and Coahuila.

Cartel enforcer

Mr Vergara said that Martinez had ordered the murder of 72 migrants in 2010, as well as that of another 200 migrants found in mass graves in the same area a year later.

He is also accused of masterminding the prison break of 131 inmates from the Piedras Negras jail in Coahuila state last month.

He is believed to have joined the Zetas cartel 10 years ago as a look-out, quickly rising through the ranks to become a hired killer.

Martinez was jailed in 2007 but sprung from prison by his comrades a year later and put in command of the cartel's operations in Tamaulipas in 2010.

The Zetas cartel has been accused of carrying out much of the violence which has plagued the northern Mexican states near the US border.

Its bloody fight with its rivals from the Gulf and Sinaloa cartels for drug smuggling routes into the United States has led to thousands of deaths.

The cartel is infamous for its use of extreme violence such as decapitations and mutilations.