Mexico City, Mexico (CNN) -- Three members of the family of a Mexican marine who died in a shootout last week were killed Tuesday in the southern state of Tabasco, Mexican President Felipe Calderon said.
Marine 3rd Petty Officer Melquisedec Angulo Cordova was fatally shot during a gunbattle that resulted in the killing of Arturo Beltran Leyva, one of Mexico's most wanted drug lords. The killing of his family members has raised speculation in Mexico that it was an act of retaliation by the Beltran Leyva's drug cartel, CNN en Español reported.
Very early Tuesday, gunmen entered the family's home and opened fire, killing Angulo Cordova's mother, sister and a third relative, the state-run Notimex news agency reported. Angulo Cordova's brother was injured in the shooting, the agency said.
Angulo Cordova was the only military fatality in last week's operation against Beltran Leyva in Cuernavaca, Mexico. Six other drug cartel members also died in the confrontation.
Beltran Leyva's death was a huge blow to one of Mexico's most violent groups, authorities said.
The killings were "a cowardly and contempible act," Calderon said in a speech Tuesday. "These reprehensible acts demonstrate the unscrupulous way with which organized crime operates."
The cartel is based out of the Pacific state of Sinaloa.
In another incident Tuesday, local media in Sinaloa reported that the state's director of tourism was gunned down, together with a bodyguard.