Mexican security officials on Friday announced the arrest of Edgar Hue cityrta Montiel, who is accused of overseeing the kidnap and murder of 72 undocumented migrants last summer in the northeastern state of Tamaulipas.

Huerta, identified by officials as a Los Zetas leader, also confessed to ordering the highjacking of six buses arriving in the municipality of San Fernanado and having the passengers interrogated and tortured to find out if they belonged to the rival Gulf Cartel.

The kidnapping and murder of 72 undocumented migrants, all from Central and South America, as they traveled toward the United States, horrified Mexico and soured relations with other countries in Latin America.

Huerta, a former soldier from the western state of Michoacan, told investigators that he ordered two trucks carrying more than 70 undocumented migrants to be stopped, the Public Security Ministry said in a Friday statement. The migrants were later murdered on a ranch in San Fernando, just south of the Texas border.

Los Zetas has diversified its criminal activities in recent years to include the kidnapping of migrants, who are abducted and requested ransom from their relatives already living in the United States.

San Fernando has generated enormous attention over the past year for crimes attributed to Los Zetas, who have fought for control of smuggling routes through Tamaulipas with the more- established Gulf Cartel.

Investigators have discovered more than 200 bodies, believed to be the remains of murdered bus passengers, buried in unmarked graves in San Fernando since April 2011.