Police commander Col. German Alfaro says those killed Sunday night ranged in age from 17 to 20 years old and that they allegedly belonged to the Barrio 18 gang.
Alfaro says heavily armed members of the rival Mara Salvatrucha gang arrived to the rough Losusa neighbourhood, located the victims in a street and shot all of them while they lay on the ground.
He says the gangs have been fighting over control of drug dealing areas.