A neighbour of Oscar Pistorius has told how she heard screams and four gunshots on the night the star killed Reeva Steenkamp.
Michell Burger - the first witness at the athlete's highly anticipated murder trial - told the court how she woke up at 3am to the sound of "terrible screams" and called security.
In front of a packed public gallery, which included Ms Steenkamp's mother June, she described hearing "bloodcurdling screams".
"She screamed terribly and she yelled for help," she said.
"Then I also heard a man screaming for help. Three times he yelled for help.
Ms Steenkamp was shot dead at Pistorius' home in February 2013
"Just after her screams, I heard four shots. It was very traumatic for me. You could hear that it was bloodcurdling screams."
When Pistorius' lawyer Barry Roux repeatedly asked if she thought Pistorius was lying, she said she did not understand how Pistorius could not have heard the screams.
Mr Roux also suggested she had in fact heard the sound of Pistorius hitting the toilet door with a cricket bat after the shooting, rather than the actual shots.
When pressed by Mr Roux whether the shots could have been fired before she woke up, she insisted she had heard gunshots.
During a tense exchange, Mr Roux also asked for details about the screams she heard between gunshots, and why details in her court testimony did not appear in her witness statement.
Pistorious' lawyer Barry Roux
He asked: "Was there continuous screaming?"
She replied: "The screaming, it went very fast. I didn't expect that that evening."
Mr Roux said sharply: "What is it that you say to me by mentioning that?"
Ms Burger replied: "I didn't sit there with a stopwatch and take down the timing of each shot, or write when she shouted.
"What I can say is that there were four gunshots, and I heard her petrified screaming."
Pistorius' home pictured after the shooting
Mr Roux said: "You are not sure and what you are now doing is adapting, you're speculating, you're trying to close all the gaps."
Ms Burger said she later saw aerial shots on Sky News which showed how close her house was to Pistorius' home. Until then she knew the athlete lived nearby, but not exactly where.
The trial started with Pistorius, wearing a dark suit and tie, pleading not guilty to murder and a series of firearms charges.
For much of the opening statement by the defence counsel, Pistorius had his eyes closed and occasionally sighed.
The defence used the statement to allege the crime scene had been "contaminated and tampered with". State prosecutor Gerrie Nel denied there had been any tampering.
Pistorius walks past Ms Steenkamp's mother (second from right)
Pistorius' team also said claims the athlete wanted to kill Ms Steenkamp "couldn't be further from the truth", and that he thought there was an intruder in his home.
After the opening statement Pistorius then fixed his gaze on the witness box, where his neighbour gave evidence for most of the day.
Earlier, there was disruption in court as a woman known only as Anna Marie - who has attempted to intervene in previous hearings - turned up at court and was surrounded and asked to leave.
Sky's Alex Crawford, who is in court, said the woman told reporters she knew Pistorius' mother, and wanted to see the judge.
She also claimed to be the ex-wife of the surgeon who amputated Pistorius' legs as a baby.
Large parts of the trial are being televised
In a landmark ruling, large parts of the case are being broadcast live by three remote-controlled cameras in court, but testimony given by Pistorius can't be shown.
The trial, which will hear from more than 100 witnesses, is scheduled to run for three weeks but could go on for longer.
The South African legal system does not have trials by a jury, so a judge is presiding over proceedings who will ultimately pronounce Pistorius innocent or guilty.
The 27-year-old double amputee faces charges of murder, illegal possession of ammunition and two additional counts relating to shooting a gun in public in two separate incidents before shooting Ms Steenkamp at his home in Pretoria on Valentine's Day last year.
He stands accused of fatally shooting the 29-year-old model and reality TV star four times through a toilet door intentionally following a jealous row and then lying extensively about it.
Pistorius acknowledges he killed Ms Steenkamp but denies murder and says he shot her after mistaking her for an intruder.
Pistorius says he was terrified at the mistaken belief that there was a dangerous intruder in his home about to hurt him and the woman he loved dearly - but he had to intervene.
If found guilty of premeditated murder, the Paralympic and Olympic athlete could be jailed for at least 25 years.
June Steenkamp - who was sitting on the same bench as members of the Pistorius family - was in court for the first time. Earlier she had said she wanted to look Pistorius in the eyes during the trial.
She glared at the star as he walked into court.
The High Court in Pretoria where the trial is taking place
At the end of the first day of the trial he was bustled out of court through crowds of photographers and journalists and into a waiting car.
Crawford said: "There were quite extraordinary scenes when Oscar Pistorius left.
"His car was absolutely mobbed, he was followed by crowds and crowds of people who ran after his car shouting and screaming.
"It was absolute chaos for 15 minutes."
:: Sky News' live coverage of the trial is under way, and a special highlights programme will be broadcast every weekday at 9.30pm.
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