Eyewitnesses say after the truck overturned, some residents and passer-bys immediately started siphoning petrol from the truck which exploded burning some people to ashes.
When The Zimbabwe Main reporter arrived at the scene three bodies burnt beyond recognition could be seen while fire brigade Chief Fire Officer Mr Savius Mugava said more people could have perished in the inferno.
Eye witnesses said the haulage truck overturned while trying to avoid a vehicle that had encroached onto its lane.
They said people jostled to siphon fuel from the tanker despite warnings by the truck driver of a possible explosion.
Unconfirmed reports say about nine people were ferried to different hospitals in Harare.
The Permanent Secretary in the Ministry of Energy and Power Development, Justin Mupamhanga who attended the scene accompanied by the director of petroleum in his ministry Mr Morgan Mudzinganyama expressed shock at the scene of the accident.
Mupamhanga conveyed his condolences to the bereaved families.
Police said investigations are underway to identify the owner of the haulage truck and ascertain the number of casualities.