Two women are in hospital after a fire at a block of flats, which police are now treating as suspicious.
The blaze at Lisle House in Clarence Square, Cheltenham, was reported at 19:55 GMT on Thursday.
A 50-year-old woman was taken to Gloucestershire Royal Hospital in a critical condition linked to smoke inhalation.
A woman in her 60s was also taken to hospital and a number of other people were assessed at the scene.
Gloucestershire Police would like to speak to anyone who may have information about the fire.