The killings occurred Sunday night in Loma Blanca, a town in the Juarez Valley. The dead included a 7-year-old girl, her mother, three teenage boys and five adult men, said Arturo Sandoval, spokesman for the Chihuahua state prosecutors' office.
The bodies were found scattered over a radius of about 12 yards (meters) around the home, suggesting some had tried to flee when they were gunned down. A trophy from the baseball game was also found at the home.
Over 30 shell casing found at the scene indicated the killers used assault rifles in the attack.
It was one of the biggest massacres in the area since the 2010 killing of 15 people in an attack on a birthday party in Villas de Salvarcar, a working-class neighborhood of Ciudad Juarez, across the border from El Paso, Texas.
Sandoval said there was no information yet on the possible motive in the Loma Blanca killings; The Villas de Salvarcar massacre was believed to have involved a case of mistaken identity, in which one drug gang attacked a party it mistakenly thought was attended by members of a rival gang.
The Juarez Valley, a largely agricultural region that stretches along the Rio Grande, has been the scene of frequent turf battles between gangs allied with the Sinaloa drug cartel, and gunmen of the local Juarez cartel.
However, violence in Ciudad Juarez and surrounding areas has dropped significantly from its peak in 2010.
For the entire state of Chihuahua, where Ciudad Juarez is located, there were 767 homicides in the first half of 2013, down from 1,205 in the same period of 2012, 1,670 in 2011 and 1,856 in 2010.
More Nation & World Headlines
Four Confederate flags left at MLK center, church in Atlanta Cincy police officer pleads not guilty in fatal shooting 3 hurt in emergency evacuation of Boeing MD-80 1:26 p.m. Will ‘Happy Birthday’ song be free to use soon? Cop indicted for murder in traffic-stop shooting Wing part a solid clue in hunt for missing Malaysian 777 1:01 p.m. Export-Import Bank excluded from highway bill House approves highway funding bill
Our new comment system is not supported in IE 7. Please upgrade your browser here.