Two boys, 11 and 13, are among four more people arrested following a blaze at a disused factory which has claimed at least two lives.
Fire crews have to wait until the building is made safe
They were arrested on Thursday on suspicion of arson with intent to endanger life following the fire at the building in Hanley, Stoke-on-Trent.
One man, 19, has been released on bail. The boys are still in custody along with a 17-year-old.
The factory was used by homeless people. More bodies may be inside.
Five men and a woman have also been arrested over the matter and released on bail.
Emergency services were called to the Hamilton Reid building during the early hours of Wednesday when the fire broke out.
Fire crews have had to wait until the building is made safe before they can begin searching for any more bodies.
Post-mortem examinations have been carried out on the two bodies already found but more tests are needed to establish their identities.