A young South African woman who pretended to be dead for more than an hour in the Bataclan theatre while gunmen massacred concertgoers has described a sudden change in atmosphere moments before the shooting began.

Isobel Bowdery, 22, said there had been a “happy” atmosphere at the venue before the ambush, with about 1000 people in the theatre to see Californian band Eagles of Death Metal play. Then the shots began to ring out.

• Authorities race to identify Paris terror suspects
• Paris terror: Aussie Emma took shots to hip
• Paris terror attacks ‘the work of the devil’

In a post on Facebook, accompanied by a photo of the bloodied white singlet she wore to the event, she said, initially, the audience had thought the noise to be part of the show.

“When the men came through the front entrance and began the shooting, we naiively (sic) believed it was all part of the show.

“It wasn’t just a terrorist attack, it was a massacre,” she wrote.

“Dozens of people were shot right in front of me. Pools of blood filled the floor.

“The images of those men circling us like vultures will haunt me for the rest of my life.

“The way they meticulously aimed at, shot people around the standing area I was in the centre of, without any consideration for human life. It didn’t feel real.”

“As I lay down in the blood of strangers and waiting for my bullet to end my mere 22 years, I envisioned every face that I have ever loved and whispered I love you. Over and over again. Reflecting on the highlights of my life.”

A video taken outside the Bataclan. Warning – graphic content.

In her terror, Ms Bowdery said she pretended to be dead for more than an hour, “lying among people who could see their loved ones motionless”.

“Holding my breath, trying to not move, not cry – not giving those men the fear they longed to see.

“I was incredibly lucky to survive. But so many didn’t.”

In total 129 people have been confirmed dead by French authorities, at least 89 of them at the Bataclan. A further 350 were injured across Paris, in six separate attacks.

Radio reporter Julien Pearce told CNN he saw the gunmen enter the theatre “very determined” and firing “randomly”, from where he was standing near the top of the stage.

He said he saw two armed men, wearing black clothing and with their faces uncovered.

“They were just standing at the back of the concert room and shooting at us. Like as if we were birds,” he said.

“It was a bloodbath.

“It lasted for 10 minutes. Ten horrific minutes where everybody was on the floor covering their head.”

Australian man John Leader, who has lived in Paris for the past 15 years, has detailed the moment he and his 12-year-old son Oscar hid behind a mixing desk when gunmen opened fire at the theatre.

He told CNN they hid behind the desk until they could flee though an exit door.

“The shooter was standing at the back of the hall and targeting people at the front. He was taking aim. He was not spraying. It was clinical. He was aiming: aim, fire, aim, fire, aim, fire,” he said.

At one point Oscar tried to stand up, but Mr Leader stopped him saying: “Stay down, these are killers.”

It is believed only one Australian, 19-year-old Emma Parkinson, was harmed in the attacks.

Ms Parkinson underwent surgery for multiple gunshot wounds to the hip, sustained outside the Bataclan theatre.

She was in a stable condition on Sunday evening.

“We are confident Emma will make a full recovery physically. Obviously there is quite a long road ahead for Emma mentally,” Ms Parkinson’s aunt Sam Gunner said.

No Australians are believed to have been killed in the attacks.

– with AAP