A fire at a block of flats is being treated as arson, police said.
The blaze at the two-storey building in Buttery Grove, Church Parade, Telford, Shropshire, caused "extensive damage", the West Mercia force said.
People from four flats were safety evacuated following the blaze at 02:55 BST on Saturday.
A number of residents from the two ground-floor and two first-floor flats were provided with housing assistance and did not need medical treatment.
Det Sgt Antony Cleobury said: "We know the attack happened in the early hours of the morning but we are appealing for anyone who witnessed anything suspicious to come forward.
"The wider community may also be able to provide us with information.
"Did you see anyone coming home late, perhaps smelling of smoke or with singed clothes? If you have any information which could help, please contact police."