Two people suffered severe burns in an early morning fire in Ottawa's west end.

Emergency crews responded to multiple 911 calls from neighbours reporting heavy smoke conditions at the rear of a home on Rideout Crescent at approximately 7 a.m. Friday.

When firefighters arrived on the scene, they confirmed the smoke was coming from the area of the roof where it connects to the exterior wall.

The fire is believed to have started in a bedroom and spread to the attic of the home.

A teen and a man in his 50s were treated at the scene for burns, and both were transported to the hospital in critical condition.

The cause of the fire is under investigation.