Limpopo police are searching for a man believed to have been behind an arson attack that claimed the lives of an elderly man and his two grandchildren.

"The incident occurred in the early hours of Friday at Sekgakgapeng village in the Mahwelereng Policing precinct outside Mokopane‚" said Colonel Moatshe Ngoepe.

"It is alleged that the entire family was asleep when an unknown suspect threw what is believed to be a petrol bomb at the house which immediately caught fire. The family of eight‚ aged between three months and seventy years old‚ were trapped inside‚" Ngoepe said.

Firefighters managed to douse the flames but a five-year-old girl was declared dead on the scene‚ while her two-year-old sister died on the way to hospital. Their grandfather later died in hospital from the burn wounds he suffered.

"The rest of the family members who survived‚ including the mother of the two deceased‚ were taken to hospital for medical treatment."

Police have since released a picture of a man who they believe could be crucial in the case.

"The police are still calling upon Bongani Abrahm Boshomane‚ aged 45‚ to report at Mahwelereng or the nearest police station to assist them on the ongoing investigations‚"said Ngoepe.

"The motive behind this incident is still unknown at this stage but domestic violence may not be ruled out‚" he added.