Oscar Pistorius wept Tuesday as his defence lawyer read the athlete's account of how he shot his girlfriend to death Valentine's Day, claiming he had mistaken her for an intruder.

Prosecutors, however, told a packed courtroom that the double-amputee known as the Blade Runner intentionally and mercilessly shot and killed 29-year-old Reeva Steenkamp as she cowered inside a locked bathroom.

Pistorius told the Pretoria Magistrate's Court at a bail hearing he felt vulnerable in the presence of an intruder inside the bathroom because he did not have his prosthetic legs on, and fired into the bathroom door.

The Valentine's Day shooting in Pistorius's home in Pretoria shocked South Africans and many around the world who idolized him for overcoming adversity to become a sports champion, competing in the London Olympics last year in track besides being a Paralympian. Steenkamp was a model and law graduate who made her debut on a South African reality TV program that was broadcast on Saturday, two days after her death.

'Horror and fear'

In a major point of contention emerged even during Tuesday bail hearing, prosecutor Gerrie Nel said Pistorius took the time to put on his prostheses, walked seven metres from the bed to the enclosed toilet inside his bathroom and only then opened fire. Three of the bullets hit Steenkamp of the four that were fired into the door, Nel said.

Pistorius said in his sworn statement that after opening fire, he realized Steenkamp was not in his bed.

"It filled me with horror and fear," Pistorius said.

Reeva Steenkamp's body was being cremated Tuesday at a memorial service in the south-coast port city of Port Elizabeth. (Stimulii/Associated Press)

The 26-year-old Olympian said he put on his prosthetic legs and tried to kick down the door before finally bashing it in with a cricket bat. Inside, he said he found Steenkamp, slumped over. He said he lifted her bloodied body into his arms and tried to carry her downstairs to seek medical help.

But by then, it was too late.

"She died in my arms," the athlete said.

Nel charged Pistorius with premeditated murder and said the athlete opened fire after the couple engaged in a shouting match and she fled to the bathroom.

"She couldn't go anywhere. You can run nowhere," Nel said. "It must have been horrific."

A conviction of premeditated murder carries a mandatory sentence of life in jail.

Chief Magistrate Desmond Nair ruled that Pistorius must face the harshest bail requirements available in South African law. That means Pistorius' lawyers must offer "exceptional" reasons for the athlete to be free before trial, besides simply giving up his two South African passports and posting a cash bond.

Pistorius sobbed softly as his lawyer, Barry Roux, insisted the shooting was an accident and there was no evidence to substantiate a murder charge.

"We submit it is not even murder," he said. "There is no concession this is a murder."

Cancelled plans

Pistorius' emotional outbursts again played a part in how the hearing progessed, as it did during an initial hearing Friday. At one point, Nair stopped the hearing after Pistorius wept as Roux read a portion of the athlete's statement describing how Steenkamp bought him a Valentine's Day present, but wouldn't let him open it the night before.

"Maintain your composure," the magistrate said. "You need to apply your mind here."

Pistorius' voice quivered when he answered: "Yes, my lordship."

Oscar Pistorius was born without fibula bones and had his legs amputated when he was 11 months old. (AP)

Affidavits from friends of Pistorius and Steenkamp described the two as a charming, happy couple. The night before the killing, they said, Pistorius and Steenkamp had cancelled separate plans in order to spend the night before Valentine's Day together at his home, in a gated neighbourhood.

Outside the court, several dozen singing women protested against domestic violence and waved placards urging that Pistorius be refused bail. "Pistorius must rot in jail," one placard said.

As details emerged at the dramatic court hearing in the capital, Steenkamp's body was being cremated Tuesday at a memorial service in the south-coast port city of Port Elizabeth. Six pallbearers carried her coffin, draped with a white cloth and covered in white flowers, into the church for the private service.

South Africa has some of the world's worst rates of violence against females and the highest rate in the world of women killed by an intimate partner, according to a study by the Medical Research Council. Professor Rachel Jewkes of the council said at least three women are killed by a partner every day in this country of 50 million.

Domestic violence advocate

Steenkamp campaigned actively against domestic violence and had tweeted on Twitter that she planned to join a "Black Friday" protest by wearing black in honour of a 17-year-old girl who was gang-raped and mutilated two weeks ago.

What "she stood for, and the abuse against women, unfortunately it's gone right around and I think the Lord knows that statement is more powerful now," her uncle Mike Steenkamp, the family's spokesman, said after her memorial.

He said the family had planned a big get-together at Christmas but that had not been possible. "But we are here today as a family and the only one who's missing is Reeva," he said, breaking down and weeping.

Pistorius has lost several valuable sponsorships estimated to be worth more than $1 million Cdn a year.

On Tuesday, the athlete was ousted from a pro-gay campaign being launched in Cape Town, organizers said. In a video axed from the campaign, Pistorius says: "You don't have to worry. You don't have to change. Take a deep breath and remember, 'It will get better."'

And Clarins Group, which owns Thierry Mugler Perfumes, said in an email that "out of respect and compassion for the families involved in this tragedy, Thierry Mugler Perfumes have taken the decision to withdraw all of their advertising campaigns featuring Oscar Pistorius."