Terrorists of North African appearance speaking perfect, accentless French stood at the back of the Bataclan theatre and calmly and methodically gunned down the audience, as they lay on the floor of the venue playing dead.

That's according to an Australian man who huddled behind a mixing desk with his son 10 metres from the gunmen.

Warning: This contains disturbing details of the attack on the Bataclan.

John Leader, 46, and Oscar, 12, had been inside the venue for 15 minutes, listening to American rock band Eagles of Death Metal, when three terrorists entered from the entrance at the back of the sold-out 1500-person theatre in central Paris.

Mr Leader did not know that about six kilometers away in northern Paris a suicide bomber had activated an explosive belt near the Stade de France, where a soccer game was being played between France and Germany.

It was the first in a series of terrorist attacks in the French capital that night. The coordinated attacks, which began at 9:20pm (local time) and spanned a period of about three hours in five locations, would kill 129 people and injure about 350 more.

Eighty nine of the dead were from the Bataclan Theatre.

Skip Twitter Tweet FireFox NVDA users - To access the following content, press 'M' to enter the iFrame. BREAKING: Explosions heard near Stade de France stadium where France-Germany match was taking place #ParisAttacks https://t.co/lFHnTcLUDE — Al Jazeera America (@ajam) November 13, 2015

Among the injured is Emma Grace Parkinson, 19, from Hobart, who was shot in the hip and is now recovering in hospital.

In the dark, Mr Leader initially thought the gunfire noise was firecrackers. Soon the crowd realised an attack was taking place.

"It was a bit of a scramble," he told Hack. "Because we were next to the mixing desk, I got on top of Oscar and was pushing him towards the mixing desk. We managed to get around the right hand side of the mixing desk and since it was dark we had no idea where these guys were."

Then the room was brilliantly illuminated by the house lights. He could see two terrorists who appeared to be of "Tunisian" or "North African" appearance. They wore "large brown sleeveless vests" that may have been made of leather. They were in their twenties, Mr Leader said.

The two men stood about three metres from the back wall and fired in the direction of the stage, hitting people whose bodies piled up at the front of the venue.

The music had stopped before the lights came on. It would later be reported the band had fled the venue by the stage door. A member of the band's crew would be killed.

The men were about 10-15 metres away and had "AK-47-style guns", Mr Leader said. They worked as a pair.

One would shoot into the front of the venue while another covered the shooter to make sure nobody was able to approach. Only one at a time would fire, he said.

They were very calm, very methodical, very slow. I watched the guy reloading. The person knew what he was doing. He wasn't panicking. This was practised. They weren't in there shooting like in an American movie ... At no point did they put the guns on full automatic. It was only semi automatic with pauses between the shots."

"It really was not firing at random. It was finding a target and then shooting and then finding the next target and then shooting," he said.

Apart from the shooting, the venue was almost silent, Mr Leader said. He said people were not calling out names.

Moments earlier in the dark, people had been screaming, but as soon the house lights had lit up the room, people froze and fell silent, he said.

"It seemed to me very silent. There was a real sense of everybody merging into a silent and non-moving mass. It was very surreal ... It was clear if you move you're dead."

Mr Leader and his son were hidden from view behind the audio mixing desk. It was a black sheet over metal scaffolding. The sound man was crouched under the desk in full view of the gunmen. The man motioned for John and Oscar to stay where they were.

"Oscar moved back towards me ... I told him to put his head down and said 'these guys are killers'. When I looked at him he didn't seem to know if this was real or if this was a joke ... I tried to rack my brains about how to get out of this."

Later he would say the mixing desk had "absolutely" saved their lives. When the lights had come on many had been caught in the open, exposed to the gunmen. They had tried to move towards the mixing desk. It was the only shelter in the room, apart from other bodies.

People were piled up. If you were at the bottom of a pile with two people on top you were probably a lot safer."

"At one point a young woman climbed over. She was in a more open position behind us. She climbed on top of us. We were on the edge of the desk and she curled on top of us, with her head still below the top of the desk."

About 10 or 15 minutes passed. One of the gunmen made a short "diatribe" about Syria. Other witnesses have reported the gunmen shouted "Allahu akbar" as they attacked.

"It was obviously perfect French with no accent," said Mr Leader, who has lived and worked in Paris for 15 years. "I knew this was to do with Syria. And I knew these guys had probably grown up in France because this was perfect French they were speaking."

The firing stopped. Mr Leader heard someone say, in French, that the men had gone. He could not see the shooters. People began stirring. He and Oscar ran a diagonal route from near the back of the theatre to an open fire exit at the front of the venue.

It was only then they realised how many had died. Bodies lay face down in pools of blood at the foot of the stage. When they were close to the stage and about five metres from the stairs going down to the street the shooting started again.

I got Oscar and pulled him flat on the floor. Unfortunately it was on top of the bodies and blood. He was trying to get up to the exit. I said 'get your head down.'"

The firing stopped once more and they ran down the stairs. Oscar lost his shoes. "He said somebody was trying to hold on to him or something," Mr Leader said. "Somebody held his shoes and he ran out in his socks."

Mr Leader was out only seconds after Oscar but they had become separated. He could not find his son. There were 10-15 dead bodies in the street. The injured were dragging themselves out. Others survivors were running away. He shouted Oscar's name up the street.

"He might have gone hit on the stairs when he was coming out ahead of me," Mr Leader said. "I came back and had a peek in the doorway. He wasn't there."

Then the shooting started again. Mr Leader ran up the street. Terrified survivors were trying to take shelter inside apartment blocks.

The residents were shouting down the numbers of digital access codes to allow them to enter the lobbies of the buildings.

Inside the Bataclan, the shooting continued.

"To a large degree it was every man to himself at that point. People were trying to get space between them and these guys."

About 100 metres from the Bataclan, Mr Leader remembered he could contact his son by phone. Oscar answered on the second ring. He told his dad he had run down the stairs and fled up the street. He had not heard his dad shouting. He was safe and nearby. They arranged to meet at a metro station.

In the taxi home they passed the scene of another, separate terror attack, where a man had shot diners in the Petit Cambodge restaurant.

Later they heard news reports that police had stormed the Bataclan about 1:20am. Three attackers were killed.

It was obviously a very harrowing experience. After two days we're starting to take the measure of what's happened. It was obviously a very harrowing experience. After two days we're starting to take the measure of what's happened.

"For Oscar we're focusing on this not being a life defining event and being more of a mishap.

"We'll see how it goes."

"The fear hasn't hit yet. It's not to say it won't."

"I don't think we're in shock. We're in the denial phase. For me at the moment it was a rough Friday night. It hasn't sunk in how lucky we were."

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