The murder trial of Olympic and Paralympic athlete Oscar Pistorius has resumed after a two-week break.

He is accused of murdering his model girlfriend Reeva Steenkamp on Valentine's Day last year.

The trial began on 3 March but Judge Thokozile Masipa granted the state's request for a postponement on 17 April to avoid conflicts with other cases.

Mr Pistorius has admitted shooting Ms Steenkamp at his Pretoria home.

However, he insists he killed the 29-year-old law graduate and model accidentally after mistaking her for an intruder hiding behind a closed toilet door.

He faces at least 25 years in prison if he is found guilty of murder.

The defence began today by calling Johan Stander, the manager of the up-market Pretoria housing complex Mr Pistorius lives in.

Mr Stander told the court he received a phone call from a distressed Mr Pistorius in the middle of the night, saying he had killed Ms Steenkamp by mistake.

"Oom (Uncle) Johan, please, please come to my house. I shot Reeva. I thought she was an intruder. Please, please come quickly," he quoted Mr Pistorius as telling him in a phone conversation minutes after the shooting.

Mr Stander also testified about previous break-ins at the estate, but was forced to admit under cross-examination that it was "generally a safe place".

Mr Pistorius's defence hinges on his assertion that he heard a noise in the middle of the night and thought it was an intruder climbing into the bathroom adjoining his bedroom.

When he heard another noise coming from the toilet he fired four shots through the door, thinking one or more intruders was behind it.

Ms Steenkamp, who was hit by at least three of the four hollow-point rounds fired, died almost instantly.