Two teenagers were fatally shot and two others were injured outside a Chicago public school on Friday afternoon, the authorities said.
The four, whose ages were not immediately known, were taken to John H. Stroger, Jr. Hospital of Cook County, said Larry Merritt, a spokesman for the Chicago Fire Department.
One boy was dead on arrival and another later died there, according to the authorities. Another boy and a girl were treated for injuries that were not life-threatening, Mr. Merritt said.
David Brown, the superintendent of the Chicago Police Department, said at a news conference on Friday that the authorities did not have any suspects in custody.
“Obviously, we are conducting a pretty aggressive investigation,” he said.
It was not immediately clear what had led to the shooting. It was also not clear if the victims were students.
The shooting occurred at about 1:50 p.m. outside Benito Juarez Community Academy, a public high school with about 1,700 students. Students were beginning to be dismissed for the weekend around the time the shooting began, Mr. Brown said.
Chicago Public Schools later announced an “all clear” for students at the school, said Tom Ahern, a Chicago Police Department spokesman.
Mr. Brown said that investigators were looking at video taken in the area, but he did not say what it showed.
“Any crimes anywhere in the city is obviously a concern to us, but especially when they’re near or around schools,” Mr. Brown said.
The chief executive officer of Chicago Public Schools, Pedro Martinez, an alumnus of Benito Juarez, said at the news conference that the city would provide support for affected children over the weekend and next week before the school semester ends.
“I’m very concerned because this happened on our grounds,” Mr. Martinez said.
Chicago Public Schools said in a statement that it would provide crisis team resources to students and staff in the coming days.
Representative Jesús “Chuy” García of Illinois, a Democrat whose district includes Chicago, said in a statement that “my heart breaks for the victims of this afternoon’s shooting.”
“I think especially of the parents,” he said, “who must now bear the unimaginable pain of losing a child.”