Two boys were hit by gunfire through a bedroom window in Azusa late Wednesday, while another teen was injured by shattered glass, police said.
Police were treating the case as an attempted murder as they continued to search for the shooter or shooters, according to officers with the Azusa Police Department.
A 13- and 16-year-old were struck inside a home in the 500 block of East Duell Street just before midnight, police said.
"It appears suspects walked up to a bedroom window (and) fired several shots into the room where the victims were seated," Azusa Police Department Sgt. Terry Smith said.
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A 17-year-old was hurt by flying glass during the shooting. All three were taken to the USC Medical Center. Official details regarding their conditions were not immediately available.
"They're doing fine, they're recuperating," said a family friend who declined to be identified.
The shooter, who fired several rounds, would have had to sneak round the rear of the property to shoot into the bedroom, according to investigators.
The next door neighbor, Rosalva Gonzalez, said at first she thought it was just firecrackers she was hearing. She saw someone drive away in a car, but could not make out who was driving.
Gonzalez said there were plenty of teens coming and going at the house, but they were pretty young and there were never any problems.
It is unknown who shot the teenagers, or whether it is gang related. Police said the victims have not been cooperating with detectives, who are treating the shooting as attempted murder.