A girl aged four and two boys aged three were pronounced dead at the scene, and a woman has been arrested on suspicion of murder.
The parents of the children are thought to be Gary and Tania Clarence, a couple who had moved to the UK from South Africa.
A reporter from BBC London 94.9 has been speaking to neighbours and it has been suggested that three of the children were disabled.
“They are a very, very lovely couple. I saw them all the time about with their children,” one unidentified neighbour said.
Police are not looking for anyone else in connection with the incident.
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