Six teens were injured when an explosive device was thrown into a backyard party in northern California, police said early Saturday.
The Manteca Police Department said officers responded to reports of numerous injuries from an explosion at a local home shortly before midnight.
"Preliminarily, we're thinking that it's a modified firework that was thrown into the backyard," Manteca police Chief Nick Obligacion told NBC News.
Around 60 high schoolers were attending a party at the home when "an unknown subject intentionally threw an explosive device over a fence" into the backyard, according to a statement from police.
There were six victims, Obligacion said. Four were treated and released with minor to moderate cuts and burns, one was transferred to a county hospital with moderate injuries and another was transported to Oakland Children's Hospital for a "more severe facial injury that doesn't require surgery," Obligacion said.
All of the victims were juveniles, he added.
