Relatives of seven people who died in a flat in Strand say they are struggling to come to terms with the tragedy.

Three adults and four children were found dead in Green Acre Terraces on Tuesday.

It is believed a fire made in a metal container in the flat caused the victims to die of smoke inhalation.

One other person is in a critical condition in hospital.

A relative of the victims has told Eyewitness News she is heartbroken.

"How can a person really feel after you've just lost seven family members at one time? I don't think there's [sic] any words or any feeling that can describe this. God knows what happened."

Police spokesperson Olebogeng Tawana says they do not suspect foul play, but will continue their investigation.

"The police will be investigating a case of an inquest to determine the cause as to how did they die."

The victims will be buried on Wednesday.