A 52-year-old Sydney woman whose car careened into a primary school, killing two boys and seriously injuring three girls, has been charged by police as the local community gathered to grieve for the victims.

The woman’s Toyota Kluger drove into a weatherboard classroom inside the school grounds of Banksia Road Public School in Sydney’s south-west at around 9.45am on Tuesday, injuring more than 20 people.

The woman behind the wheel of the SUV was uninjured and has been charged with dangerous driving occasioning death and negligent driving.

Of the 24 Year 3 pupils inside at the classroom, 18 were assessed for injuries at the scene and five were taken to Westmead Children’s Hospital, where the two boys were later pronounced dead.

Two other children aged 8 and 9 were recovering in hospital.

The school community gathered at the site overnight to hold a vigil for the children, and counsellors will be on hand when the school reopens Wednesday morning.

Onlookers rushed in to free the children pinned under wreckage, with some reportedly lifting the side of the SUV before administering first aid until help arrived.

One of the first responders, a man who asked to remain anonymous, said he and three others lifted the vehicle off a boy trapped beneath.

“I heard a big bang from across the road, so I went over and I heard some kids screaming and crying,” the man told the ABC.

“I saw the car had crashed into the classroom. There were kids and debris and blood everywhere.”

Paramedics arrived to “a scene of carnage” with “distressed and overwhelmed children and teachers”, NSW Ambulance superintendent Stephanie Radnidge told reporters.

It was “pandemonium”, Ms Radnidge said.

Police said they were investigating the incident as an accident not an intentional act.

They will examine the vehicle involved to determine whether there were any mechanical problems.

More than 100 mourners took part in a minute’s silence at a vigil held outside the school on Tuesday evening, with many placing flowers outside the school’s gates in memory of the two boys killed.

Year 4 student Mariam Issmail was in a nearby classroom when the SUV ploughed into the school.

“We were just doing work and all of a sudden we heard this big bang,” she told reporters.

Mariam said multiple schoolmates were injured, adding that twin girls were among those hurt.

“[Students] were screaming, saying they wanted their mum, I want help.”

There were chaotic scenes at the school as frantic parents raced to check on the welfare of their children.

The car that tore through the classroom is towed from the scene. Photo: ABC

Chaplains were on site providing support for paramedics responding to the incident, NSW Ambulance said.

Power was cut to the affected building, which suffered a partial structural collapse.

The female driver of the car was taken to hospital for mandatory blood and urine tests.

“We’re not looking at this as an intentional act,” a NSW police spokesman said.

“It is an active crash investigation. It would be only speculation to believe we know what caused this event at this time.”

The driver was granted conditional bail and will appear at Bankstown Local Court on November 29.

NSW education minister Rob Stokes said the grief was beyond comprehension and the government’s first priority would be to support students and families.

“This will not be a quick process and we will work together with the school community to provide whatever assistance we can,” he said.

Premier Gladys Berejiklian visited the school on Tuesday to pay her respects.

-with wires