Updated February 02, 2018 16:40:32

Police have arrested a 12-year-old girl suspected of shooting four students, one in the head, inside a Los Angeles high school classroom.

A 15-year-old boy was taken to hospital in a critical but stable condition after being shot in the head, while a 15-year-old girl with a gunshot wound to the wrist was taken to a hospital in fair condition, Los Angeles Fire Department spokesman Erik Scott said.

Two more children were grazed by bullets.

Police arrested the female student and recovered a gun after the shooting that happened just before 9:00am (local time) at Salvador B Castro Middle School, west of the city's downtown.

Preliminary information indicated she was 12, said Los Angeles Unified School District Police chief Steve Zipperman.

Authorities did not immediately identify a possible motive, saying the investigation was in its early stages.

Boy 'extremely lucky'

The most seriously injured victim was brought to Los Angeles County-USC Medical Centre and remained in intensive care but was doing well.

"This child was extremely lucky," trauma surgeon Aaron Strumwasser said.

"The trajectory of the bullet did not hit any vital structures that were an immediate threat to life."

The girl wounded in the wrist also remained hospitalised but was described as resting comfortably.

Three other victims, including a woman, were initially described as having suffered abrasions.

But the two children actually had grazing gunshot wounds, Dr Strumwasser said. They were treated and released.

Worried parents rush to school

Television news footage showed a girl with dark hair wearing a sweatshirt being led out of the school in handcuffs a short time after the shooting, while police cars blocked an intersection near the school and parents gathered at the street corner, talking on their phones and awaiting word about their children.

Photo: Parents wait outside the school for news about their children (AP: Damian Dovarganes)

The school's campus remained in lockdown later in the morning but had been declared safe, Chief Zipperman said.

"We will attend to the needs of these students who witnessed this very carefully, with the understanding this is very traumatic," he said.

"We have our school mental health folks that are here to support the needs of the students."

Parent Claudia Anzueto, 41, said her 12-year-old son was crying when he used someone else's mobile phone to call her.

She said he told her he was in a classroom next to the classroom where the shooting happened, heard a gunshot and knew the suspect.

School has gun prevention strategy

The district has a policy requiring every high school campus to conduct daily random searches by metal-detector wands at different hours of the school day for students in the sixth grade and up.

Officials have not said whether students at the school were subject to any weapons screening on Thursday.

Ms Anzueto said there were no metal detectors at the school.

"Not safe, not safe, very insecure," she said.

"I fear for my son's life. You really hear about things like this in the news, and just to hear that something like that happened so close to home, it scared the life out of me."

AP

Topics: schools, crime, united-states

First posted February 02, 2018 11:54:06