Costa del Sol police arrested on Thursday eight people suspected of being involved in Tuesday night's gun battle in the Tres Mil Viviendas district of Seville.
They are said to be members of the La Perla gang and have been wanted since fleeing the Andalusian capital, according to national daily El Pais.
After the girl, known as Encarnación S.S., was killed in her home by gunmen who are believed to have confused her house with that of a rival, police have locked down the streets of the area to avoid recriminations and the outbreak of open gang warfare.
The girl's parents were also injured in the attack.
Sources close to the investigation suggest that the intended target of the shooting was the window of the house next door to that of the victims.
Investigators tracked the key suspects to an apartment in Calahonda, Mijas, near Malaga.
They successfully raided the property, arresting eight people and seizing three pistols, 8KG of cocaine and €150,000 in cash.
Those present were taken immediately into custody in Seville and placed under the watch of heavy security.
Police sources said that the most difficult task remaining would be to identify the individual gunman responsible for the girl's death, given that a number of different people and firearms were involved.
An ongoing confrontation between gangs over the control of drug supplies in the area is believed to have been behind the shooting.
Although the girl's parents are understood to be distantly related to members of a rival gang, Los Marianos, they are not thought to be involved with gang activities.
The girl was buried on Thursday morning in Seville's San Fernando cemetery.