Two teens were injured in a drive-by shooting on Flagstaff Road early Saturday morning.

According to a release from the Boulder County Sheriff’s Office, two males from Thornton were standing outside their parked vehicle in the Crown Rock Trailhead in the area of the 2300 block of Flagstaff Road when someone in a passing vehicle shot them at 4:30 a.m. Saturday.

One victim, a 17-year-old, sustained a serious injury to his leg that required surgery. The other victim, an 18-year-old, had a minor injury and was treated and released.

Investigators said they think a sedan was possibly involved in the shooting, but do not have a make, model or color.

Any members of the public with information or who witnessed unusual activity along Flagstaff Road on Saturday morning, specifically between the hours of 3:30 and 4 a.m., are asked to contact the Boulder County Sheriff’s Office tip line at 303-441-3674 or BCSOtips@bouldercounty.org.

The public may also submit tips through Colorado Crime Stoppers at 800-222-TIPS (8477).

The Boulder County Sheriff’s Office, Boulder Police Department, Boulder Emergency Squad, Search and Rescue Dogs of the United States and the Boulder District Attorney’s Office all responded to the call.