At least five people died in a night shooting near Rock Hill, a small town in South Carolina.
Two children and their grandparents are among the victims.
The incident on the day American President Joe Biden is preparing to announce a crackdown on firearms.
"Gun violence is an epidemic. It is a public health crisis. I am proud to be part of a" president-led "administration that has long fought for common sense measures on gun safety. Today it represents a big step forward to make our children and our communities safer ". White House spokesperson Jen Psaki tweeted it. Joe Biden is preparing to present a close on firearms in the next few hours.