A STABBING that left a two-year-old girl dead allegedly started with her parents arguing over a trip to the beach.

The Daily Telegraph reports the girl was found fatally wounded in her family's unit after her mother was repeatedly stabbed in front of two young neighbours in the carpark at Canley Vale, in Sydney's south-west.

It is alleged the Afghan woman, 24, had been fighting with her husband over going to the beach and he had chased her with a knife.

The woman had banged on a neighbour's door seeking help about 6.45pm Saturday.

A neighbour's young sons were in the car park and screamed when they saw the attack, which left the woman with chest and shoulder wounds and slumped in the entrance to the building .

Her 32-year-old husband was under police guard in hospital last night after their daughter was found fatally stabbed in their unit.

A female neighbour, who asked not be identified, said the woman had joined her husband from Afghanistan about a year-and-a-half ago, and the couple had lived in the unit for about six months.

The husband, a security guard, had migrated from Afghanistan about five years ago, she said.

The neighbour said the couple had been arguing because the wife wanted to go to the beach and her husband would not let her.

The woman left their unit and went downstairs to a friend's apartment for about two hours.

Later that day, the woman fled her apartment and frantically knocked on her friend's door again, pleading for assistance.

The neighbour's sons, who were interviewed by police yesterday, then allegedly saw the husband stab his wife in the wrists, chest, stomach and face.

It is alleged the husband then returned to his apartment and locked the door.

Police attempted to make contact but could not enter until about 8pm, when they found the little girl suffering stab wounds.

She was taken to hospital but died shortly before 10pm.

The husband was found in the unit with stab wounds to his chest.

He was placed under arrest and taken to hospital, where he remained in a serious but stable condition.

His wife was at the same hospital, where her condition is listed as stable.

Another neighbour said she had opened her front door and seen the wife covered in blood.