Abi Gbago, chief executive of Newham Council, said it would provide an update once its investigation concludes.
She said: “Yesterday was a heartbreaking and tragic day for all concerned, and we are united both in our grief, and in our determination to ensure the family are fully supported.
“What they have been through with the loss of Aalim, their child, is truly devastating and they will need time and space to mourn such a terrible loss.”
The Boleyn Trust, which runs New City Primary School where the five-year-old attended, said: “Aalim was a beautiful, happy and caring child, he was much loved by his family and all the staff at New City.
“This is a terrible tragedy and our thoughts and prayers go out to his family at this sad time.”
Asim Uddin, mosque leader at Masjid Ibrahim Plaistow, described Aalim’s death as “shocking” and said the community was “sharing the grief”.
He said: “We are fully supporting the family. We are all standing side-by-side with the family and making sure there is support.”