MEXICO CITY (AP) — Mexican authorities said Monday that the principal line of investigation in the murder of a top executive from Mexican media conglomerate Grupo Televisa is robbery.

Mexico state prosecutor Alejandro Gomez Sanchez also said that a bodyguard for the slain Adolfo Lagos who witnessed the attack told investigators he believed one of the attackers was wounded.

Lagos, who headed Televisa's phone and internet arm Izzi, was shot to death Sunday while bicycling near the famed Teotihuacan pyramids outside Mexico City.

The media giant expressed its condolences for the family of Lagos.

The state prosecutors' office had said in a statement Sunday that Lagos was wounded by a gunshot while riding his bike and died later at a nearby hospital.

Mexican President Enrique Pena Nieto said via Twitter that the federal Attorney General's Office would participate in the investigation.

In the Gulf coast state of Veracruz, armed men killed a mayor-elect Monday. The state prosecutor's office said in a statement that it was investigating possible links to a fuel theft ring, but also to local police.

Merida Mar Dominguez, director of the New Alliance party in Veracruz, said some 30 armed men arrived in SUVs, dragged Santana Cruz Bahena from his home in broad daylight and executed him in front of his family.

Cruz Bahena served as mayor of Hidalgotitlan in eastern Veracruz from 2010 to 2013 as a member of the Revolutionary Institutional Party. He was elected in June as a candidate for New Alliance and was scheduled to take office Jan. 1.