(CNN)One teen is dead and two remain hospitalized after a shooting Monday outside a high school in Des Moines, Iowa, police said.
The deceased victim was identified as a 15-year-old boy who was not a student at the school. The other two victims -- a 16-year-old girl and an 18-year-old woman -- were students at the school, police confirmed Monday night. The two are in critical condition.
The gunfire appears to have come from a passing vehicle, police said.
The incident is at least the 13th shooting at an American campus with K-12 students in 2022, according to a CNN tally. It is the fourth homicide in Des Moines, police said in a news release.
Police started getting calls around 2:48 p.m. CT (3:48 p.m. ET), said police Sgt. Paul Parizek. A news release from Des Moines police said officers received multiple calls reporting gunfire at the school and multiple injuries.
Upon arrival, police found the three with gunshot injuries. All were taken to area hospitals.
Police detained potential suspects, Parizek said. No charges have been filed at this time, the release said.
The school went under lockdown for more than 40 minutes, but students were later dismissed around 3:30 p.m. when police gave an all-clear, according to a statement from Des Moines Public Schools.
East High School will be closed Tuesday, the school division said.
"The DMPS grief team will be available at East High for students and staff beginning tomorrow through the remainder of the week. School counselors will be available at our other schools for students who need additional support," the division said in a news release.
"Des Moines Police Department detectives continue to investigate this incident. Witnesses are being interviewed, evidence examined, investigative leads followed, and multiple search warrants are being executed," Des Moines police said in a news release.
The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) of Kansas City is on scene providing assistance in the investigation, the agency tweeted. Other agencies assisting with the investigation include the Iowa State Patrol, Polk County Sheriff's Office, the FBI and the Des Moines Public Schools Department of Public Safety.