The chief prosecutor in the murder trial of Oscar Pistorius accused him on Monday of "tailoring" his version of how he killed his girlfriend, as the grueling cross-examination of the track star went into a second week.

Prosecutor Gerrie Nel has accused the athlete of hiding the truth about the death of Reeva Steenkamp, whom he shot last year through a closed toilet door in his luxury home in Pretoria, South Africa.

His questions have sought to undermine Pistorius' reliability and credibility and to portray the Olympic and Paralympic athlete as someone who was inventing his version of events to suit his story.

Nel, known in South African legal circles for his bulldog-like approach to questioning, has gone through minute detail regarding the early hours of Valentine's Day 2013, repeatedly challenging the double amputee over his actions that night.

On Monday, in yet another intense scrutiny of his story, the prosecutor again tried to exhaustively highlight apparent inconsistencies between Pistorius' bail application and his testimony in court to show he is "tailoring his evidence" to suit the defense case.

"I am going to point out to you how improbable your version is," Nel told the runner, who sat immobile, staring ahead at the judge as he answered questions.

The prosecution's argument is that Pistorius shot Steenkamp intentionally after a heated argument. Pistorius does not deny shooting her but insists that he mistook her for an intruder.

"I did not fire at Reeva," Pistorius told the court, his voice breaking, causing a second brief adjournment in the day's proceedings so he could gather himself.

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Oscar Pistorius denied he picked on girlfriend Reeva Steenkamp, his murder trial heard Thursday, as the chief prosecutor sought to portray the track star as an arrogant hothead who is reckless with guns.

In a second day of blunt and aggressive questioning, prosecutor Gerrie Nel accused the double amputee of blaming other people for his mistakes, as he sought to prove the Olympic and Paralympic athlete murdered Steenkamp on Valentine's Day last year.

Nel began by picking apart message exchanges between the couple, accusing the runner of screaming at his girlfriend and acting selfishly toward her.

"I didn't treat her badly," Pistorius replied.

Asked if Steenkamp had lied when she said he picked on her incessantly, Pistorius replied: "She never lied."

He later added: "Reeva was never scared of me."

Nel highlighted an incident in which Steenkamp complained in a message that Pistorius asked her to stop chewing gum. He also read a message in which she defended herself against Pistorius' accusations that she flirted at a party.

"You were strong enough in that relationship to say stop your voices, stop your accents, stop chewing gum," Nel said. But Pistorius replied he gently told her to stop chewing gum before they got on camera at an event.

Nel said Pistorius never responded to Steenkamp's message in which she said, "I'm the girl who fell in love with you."

"We did a search ... the phrase 'I love you' appears twice on her phone, to her mother," the prosecutor said.

"Because it was all about Mr. Pistorius," Nel said. The athlete said he never got the opportunity to tell Steenkamp he loved her.

'You will blame anybody but yourself'

In his second day of cross-examination, Pistorius faced persistent questions about what happened on the night he shot Steenkamp. Nel said Pistorius' version of events on the night of the killing "is a lie" and accused him of "adapting" events to suit his account.

The runner recounted waking up during the night and getting out of bed to close the doors to a balcony, shut the curtains and move fans into the room. Steenkamp is then thought to have gotten out of bed, but the athlete said he was unable to see her because he had his back turned and the room was dark.

Pistorius insisted again that the shooting was an accident and he did not intentionally fire four shots.

Nel, with a reputation as one of South Africa's toughest attorneys, has sought to portray Pistorius as negligent with firearms.

"You will blame anybody but yourself," he said to the 27-year-old, cross-examining him about a separate incident in which Pistorius is accused of firing a pistol in a restaurant in January 2013.

Pistorius said the gun was given to him by a friend under a restaurant table and went off by itself as he tried "to make it safe." He had wanted to see the gun but conceded he hadn't checked the magazine first. Police Capt. Christian Mangena gave evidence earlier in the trial, saying the weapon could fire only if the trigger was pulled.

The athlete said he could not explain how the gun went off, and he questioned the decision of his own defense lawyer, Barry Roux, not to cross-examine Mangena on his evidence.

"Now you blame counsel Mr. Roux," Nel said.

Pistorius, the most composed he has been in days, said he repeatedly took the blame for the incident, but the prosecutor tried to poke holes in his declaration.

"This is incredible. You never touched the trigger, the gun went off. You took the blame, you took responsibility, but no one remembers," Nel said.

Pistorius also said two witnesses, an ex-girlfriend and a friend, were lying about an incident in which the runner is alleged to have fired his gun out the sunroof of a car. And he said he wasn't guilty of a fourth charge against him: illegal possession of ammunition found in a safe in his home after Steenkamp's death.

"You just don't want to accept responsibility for anything," Nel told Pistorius, whose answers to the accusations were short denials.

'You shot and killed her. Say it'

A day before, a defiant Nel bluntly barked at the Olympic star on the stand: "You shot and killed her. Say it - 'I shot and killed Reeva Steenkamp,' "

No one disputes that Pistorius killed Steenkamp. But the prosecution is trying to prove beyond a reasonable doubt that he did so knowingly and intentionally.

The runner has admitted to the killing, but he said he mistook Steenkamp for an intruder in the bathroom when he fired through the door and killed her.

Before Nel went after Pistorius, Roux had tossed his client a question to drive that argument home. He asked Pistorius if he intentionally killed Steenkamp.

"I did not intend to kill Reeva or anybody else for that matter," he replied.

In a dramatic opening to his cross-examination Wednesday, Nel shocked the Pretoria court when he confronted Pistorius with a graphic photograph of Steenkamp showing the side and back of her skull, her hair matted with blood.

Pistorius broke down and sobbed as Nel pushed him repeatedly to take responsibility for her killing.