A man has been arrested in connection with a house fire in which a woman died and her daughter was badly burnt.
Three other women and a man were also injured in the blaze at the house in Cateswell Road, Tyseley, early on Wednesday.
Post-mortem tests showed the 52-year-old woman died because of smoke inhalation. Police said the 16-year-old girl was still "fighting for her life".
Police said a 56-year-old man had been arrested on suspicion of murder.
West Midlands Police said on Thursday forensic investigations had confirmed the fire was started deliberately.
The identity of the dead woman still has yet to be released officially.
Det Insp Ian Iliffe said police were treating the woman's death as murder and the other injuries as attempted murder.
He urged anyone who had been in the area at the time of the fire to contact police.