A shooting near a US high school left five teenagers wounded on Monday, police said.
Officers in Aurora, Colorado were called to a park near Central High School where they found five people aged between 14 and 17 had been hurt, the Aurora Police Department said.
"Unknown suspect who is no longer on scene," the police said on Twitter. "5 total people have been transported to the hospital.
"Incident did not happen inside of the school but just north at Nome Park."
Local television stations broadcast aerial footage of the park, showing law enforcement officers walking around.
Also visible were nearby houses, one of which appeared to have incident tape around it.
The local CBS affiliate reported on its website that there were emergency vehicles in the car park of Aurora Central High School, and several adults had gathered outside the school, many of them talking on phones.
Colorado is no stranger to gun violence, having suffered two of the most infamous mass shootings in US history.
In 1999, two boys shot and killed 12 classmates and a teacher at Columbine High School.
Then in 2012, a heavily armed man entered a movie theater in Aurora, murdering 12. The gunman is now serving a life sentence without the possibility of parole.
In March of this year, a gunman killed 10 people, including a police officer at a grocery store in Boulder County, 50 kilometers (30 miles) outside Denver.
After a year spent largely learning online, US schools have returned to the classroom, reviving the fear of on-campus shootings, with multiple small-scale incidents reported in recent weeks.
More than 256,000 students have been exposed to gun violence in US schools, according to data compiled by The Washington Post.
The figure includes those caught up in the violence, such as witnesses, and those forced to evacuate educational institutions when gunfire erupted.
According to a Post database, there were 29 school shootings in the United States in 2018 and 27 in 2019. The Post figures do not include shootings at colleges or universities, suicides or accidental discharges.
The deadliest recent school shooting in the United States took place in 2018, when 17 people were killed by a former student at a high school in Parkland, Florida.
Every mass shooting provokes anguished calls for gun reform in the US.
Tighter gun control is overwhelmingly popular with Americans -- but Republicans have long stood against what some view as any infringement on their right to bear arms.
