A firefighter was taken to hospital with non-critical injuries early Saturday morning after crews were called to two homes in Bonnie Doon.
The first call was to a home near 87 Street and 89 Avenue at 3:18 a.m.
There was a fire in the back of the house which quickly spread to the attic, a spokesperson for Edmonton Fire Rescue Services said.
The fire was under control at 3:56 a.m. and declared out at 4:56 a.m.
Crews were also called to another house fire a few doors down. The call came in at 3:41 a.m. and firefighters arrived to find the house engulfed in flames. That fire was called out at 10:18 a.m.
The EFRS spokesperson said four residents from one home are being provided with support, while one resident is staying with a neighbour.
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One firefighter was taken to hospital. No other injuries were reported to EFRS.
Edmonton police were on scene, but EFRS could not confirm if police are involved in the investigation.
READ MORE: 2 Bonnie Doon fires deliberately set: Edmonton fire
On Monday, EFRS confirmed the two house fires were deliberately set.
A news release issued Monday afternoon said fire investigators came to the conclusion after two homes were set on fire April 27. The two blazes caused a total of $910,000 in damages.