The South African pleaded not guilty to the premeditated murder of Reeva Steenkamp on February 14 last year, as his trial began today.

He says he mistook her for an intruder when he shot four times through a toilet door in his Pretoria home

Three of those bullets hit Steenkamp.

Neighbour Michelle Burger said she heard cries for help, then shots.

"She screamed terribly and she yelled for help," she told the court in Pretoria.

"Then I also heard a man screaming for help.

"Three times he yelled for help."

June Steenkamp (left), the mother of Reeva Steenkamp, said she wanted to look Oscar Pistorius in the eye as she attended his trial ©AFP/Getty Images



She said she then called security, before hearing gunshots.

"It was very traumatic for me. You could hear blood curdling screams," added Burger.

Steenkamp's mother was among those in court for the day's proceedings.

Judge Justice Dunstan Mlambo last week gave the go-ahead for parts of the trial to be televised live.

Pistorius' guilt or innocence will be decided by judge Thokozile Masipa

Burger's testimony was not televised - but audio of it and the entire trial is being broadcast.

The athlete, who appeared calm throughout proceedings, has also been charged with illegally possessing ammunition.

Double amputee Pistorius won three golds on the track in Beijing 2008, and two golds at London 2012 - in the 400 metres T44 and the 4x100m relay T42-T46.

The trial is expected to last at least three weeks.