Washington, Mar 8 (IANS): Three teenagers are in critical condition after a shooting outside a high school in Des Moines, the capital city of midwestern US state of Iowa, on Monday afternoon, authorities said.

The victims reportedly included two boys and one girl and they were all taken to the hospital, Xinhua news agency reported.

Police said they started receiving calls around 2:48 p.m. CT (2048 GMT) and have detained possible suspects.

Des Moines police tweeted earlier that there were "multiple shooting victims" outside East High School, located about 1.5 miles (about 2.4 km) northeast of the city's downtown.

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

"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.