Two teenagers killed in US school shooting

Two students have been killed and an instructor injured in a shooting at a Des Moines school in the United States state of Iowa.

The shooting, which police said was targeted, took place at an alternative educational program designed to keep at-risk youth away from trouble.

The injured man was identified as the program's founder - a rapper who left a life of gangs and violence and has been dedicated to helping youth in Des Moines.

Police said on Monday one man had been charged over the shooting and two other people remained in custody.

Preston Walls, 18, of Des Moines, was charged with two counts of murder and one count of attempted murder for the shooting at the Starts Right Here program.

He was also charged with criminal gang participation.

Authorities said the shooting was the result of an ongoing gang dispute.

Police said Walls was on supervised release for a weapons charge and had removed his ankle monitor 16 minutes before the shooting.

"The incident was definitely targeted. It was not random. There was nothing random about this," Sgt Paul Parizek said.

Two Des Moines teens, an 18-year-old male and a 16-year-old male, were killed.

William Holmes - a 49-year-old rapper who founded the program and goes by the stage name Will Keeps - was injured and was undergoing surgery on Monday evening.

Police said Walls and all three victims were at the school on Monday when Walls entered a common area where Holmes and the two students were.

Walls allegedly had a 9mm handgun with an extended ammunition magazine in his possession, police said, although they did not specify if he was displaying the weapon.

Holmes tried to escort Walls away from the area but Walls pulled away, "pulled the handgun and began to shoot both teenage victims", police said in a statement.

Holmes was standing nearby and was also shot, then Walls ran away, police said.

Responding officers saw a suspicious vehicle leaving the area.

Officers stopped the vehicle but Walls ran away and was arrested a short time later.

Police said a 9mm handgun was found nearby. The ammunition magazine - which has a capacity of 31 rounds - contained three.

Des Moines Mayor Frank Cownie said the people in the vehicle with Walls were also teenagers.

"That brings a total of five families of teenagers affected by youth gun violence in a matter of minutes on a Monday afternoon, right here in our capital city," Cownie said at Monday's City Council meeting.

"This is a growing and alarming phenomenon in our country, and one we've seen too often in the past and again today in the city of Des Moines."

The shooting was the sixth at a school in the US this year in which someone was injured or killed but the first with fatalities, according to Education Week, which tracks school shootings.

The website said there were 51 school shootings last year involving injuries or deaths and there have been 150 since 2018.

In the worst school shooting last year, 21 people were killed in an elementary school in Uvalde, Texas.