A man and his four-year-old daughter died after they were doused with petrol and set alight, allegedly, by his girlfriend.

Khulekani Mshibe and the couple's little girl died from severe burn wounds sustained on Sunday at their home in Zondi, Soweto.

The girl died at Bheki Mlangeni District Hospital in Jabulani, while Mshibe later died after being transferred to Chris Hani Baragwanath Academic Hospital.

The woman and the couple's other daughter, aged one, who were also burnt during the incident, are in a critical condition at Chris Hani Baragwanath Hospital.

When Sowetan visited their home yesterday, neighbours said the couple's relationship had been volatile and they had heard them argue frequently.

One neighbour, who asked not to be named, said he had ignored the noise coming from the couple's home on Saturday night as simply another dispute.

"We knew that they fought a lot. We would frequently hear them arguing.

"The woman was shouting at Khulekani and was accusing him of cheating and that she would kill the kids and herself if he left them," he said.

He said the woman had apparently locked their shack's door with a chain, trapping the family inside before setting up the blaze.

"It seems like when they all went to sleep she got up, locked the door and doused them with petrol before setting everyone on fire," he said.

Sizwe Nkomo, another neighbour, said residents struggled to rescue the family of four while the fire engulfed their shack.

"The children's screams were chilling and we heard them from a few houses away. They could not escape and we could not enter the shack," he said.

Nkomo said community members tried in vain to put out the blaze with water carried with buckets.

Yesterday, the woman's relatives were clearing the debris from the burned shack. Mshibe's brother, Simphiwe, said the family was shocked by the incident.

"We didn't expect something like this to happen although we knew they had problems," he said.

He said they were waiting for the elders to arrive from KwaZulu-Natal in order for both families to have a meeting.

Police spokesman Captain Hector Netshivhodza said they were investigating an inquest and an attempted murder case.

"At the moment we haven't been able to question anyone because nobody saw who started the fire or who was there around the time the fire started. No arrests have been made," he said.