White House Press Secretary Karine Jean-Pierre has opened her daily press briefing by speaking about the school shooting in Georgia.

"Kids across the country are heading back to school for the new year," she says. "Today is supposed to be an exciting day for parents... but instead, we're seeing another horrific shooting."

She urges lawmakers "to do something", saying "enough is enough".

"We need universal background checks. We need to ban assault weapons and high capacity magazines," she says.

US President Joe Biden has just released a statement on the shooting, saying he and First Lady Jill Biden are "mourning the deaths of those whose lives were cut short due to more senseless gun violence".

"What should have been a joyous back-to-school season in Winder, Georgia, has now turned into another horrific reminder of how gun violence continues to tear our communities apart," he says.

"We cannot continue to accept this as normal."

The president went on to call for a ban on assault weapons and high capacity magazines as he has called for before, as well as other gun control measures, including safe storage of firearms.

Four people were killed in the shooting at Apalachee High School, according to the Georgia Bureau of Investigation.

Nine people were taken to the hospital with injuries, the bureau added in a new statement.

They also said the suspect was alive and in custody.

Some more images have come in of parents reuniting with their children, with a heavy police presence surrounding the school:

Image source, Getty Images

Image source, Getty Images

Image source, Getty Images

Earlier, we had a brief update from Sheriff Jud Smith. He said multiple were injured in the "evil" attack.

You can watch his comments in the video above.

We've just heard from US Attorney General Merrick Garland, who says the FBI and the bureau of alcohol, tobacco, firearms and explosives are on the scene and working with local partners.

Garland says the government is still "gathering information".

"I'm devastated for the families who have been affected by this terrible tragedy.

"The justice department stands ready to provide any resources or support that the Winder community needs in the days ahead," Garland adds.

Family members of students at the high school have been speaking about the events that took place there this morning.

Shirly Powers, the grandmother of an Apalachee student, tells NBC News that her daughter called her at work "screaming that there was a shooter" at the school.

Her daughter "begged me to get there as quick as possible", Powers says.

WSB-TV, a local Atlanta outlet, spoke to a mother who said her son's teacher locked the door and barricaded students inside when they heard shots nearby.

We're getting some of the first pictures from the scene in Winder, Georgia, where students are being reunited with their families on the school football field:

Image source, Reuters

Image source, Reuters

We're hearing from the county sheriff, Jud Smith, now. He tells reporters that police received a call at 21:30 local time reporting an active shooter.

Smith says there were multiple injuries in an "evil" attack at Apalachee High School in Winder, about 50 miles from Atlanta.

He says students were in the process of being reunited with families.

"This is going to take multiple days for us to get answers as to what happened and why this happened," he adds.

He did not answer questions from reporters.

Two people have been killed and possibly four people were injured in the shooting at Apalachee High School, law enforcement sources have told BBC's US partner, CBS News.

US President Joe Biden has been briefed on the situation at Apalachee High School in Winder, Georgia.

His administration says it is coordinating with federal, state, and local officials.

Brandon Drenon
US reporter

Apalachee High School in Winder in Barrow County, was put on lockdown on Wednesday morning as the students were escorted outdoors to a nearby designated safe zone.

Dozens of police officers gathered at the school, where approximately 1,900 students are enrolled.

Footage from a helicopter at the scene showed emergency responders treating multiple people, according to a local Fox News affiliate.

After the school was cleared, students were released to their families, some picked up by their parents directly, others sent home by school bus.

The Georgia Bureau of Investigation said it was assisting local officers and advised “anyone near the area to stay clear while authorities investigate”.

We're bringing you updates from Georgia, where a shooting took place at Apalachee High School in Winder, near Atlanta.

Police say there have been casualties and that one suspect is in custody. They have yet to release information about those who were harmed.

The school has said the building is secure and that students are being released to their families.