(CNN) One person is dead and seven others are wounded after a shooting at a graduation party in Clarendon County, South Carolina, the sheriff's office there said.
"At least 60-70 rounds" were fired after two cars approached the lawn party, with one of them driving onto the lawn, where about 150 people were gathered Saturday night, the Clarendon County Sheriff's office said in a release.
The victims include a 12-year-old, a 14-year-old, two 15-year-olds, a 17-year-old, a 32-year-old and a 36-year-old. The 32-year-old woman died from her injuries Sunday morning, the sheriff's office said.
It is unclear if shots were fired at specific people or at random, according to the release, but officers believe the incident to be gang-related.
It is also unclear whether anyone attending the party returned fire, according to the release.
There have been at least nine mass shootings in the country since Friday, including one in Philadelphia where three were killed and 11 wounded, and one in Chattanooga, Tennessee, that left three dead and 14 wounded.
According to the Gun Violence Archive, there have been 246 mass shootings in the United States this year, defined as incidents in which four people or more are shot, not including the shooter.