Washington, Mar 8 (IANS): A 15-year-old boy has died, while two others remain in critical condition after a shooting outside a high school in Des Moines, the capital city of the US state of Iowa, authorities said on Tuesday, adding that possible suspects have been detained.

The two injured were female teenagers, aged 16 and 18, emergency officials told reporters.

Police said they started receiving calls at 2.48 p.m. on Monday of gunfire reported from a passing vehicle.

Des Moines police had tweeted earlier that there were "multiple shooting victims" outside East High School, located about 2.4 km northeast of the city's downtown area.

Officials have not released the victims' identities, nor have authorities confirmed whether they were students.

The school was temporarily on lockdown, but has been given the all-clear, Des Moines Public Schools said in a statement on Monday afternoon.

"Police are actively investigating," the statement read. "Students are dismissing on time."

The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) Kansas City Field Division, which covers states including Iowa, tweeted that special agents from its Des Moines field office are assisting police with the investigation.

"This is a dark day for the city of Des Moines," police chief Dana Wingert said Monday evening.

"Another tragic loss of life. Everyone of them is tragic, everyone of them is pointless."

As of Monday, more than 9,100 people in the US have died or been injured due to gun violence this year, according to the Gun Violence Archive.

The incident at the Des Moines high school was the 24th school shooting in 2022 in the US, the non-profit added.