FIFA president Sepp Blatter said:
I'm deeply saddened by the tragic death of workers @corinthians arena today. Our heartfealt condolences are with the families.
More top news
A 61-year-old woman has been taken to hospital this morning with stab wounds following an incident at a school.
An investigation is continuing into crashes at a motorbike race in North Yorkshire, which left 12 spectators injured - three seriously.
The man was taken early this morning to a south London police station where he remains in custody.