Police are investigating a suspicious early morning three-alarm fire in Parkdale on Wednesday.

Flames broke out at about 4 a.m. this morning on the second floor of a vacant rooming house on 114 Spencer Ave., near King and Dufferin Streets. The fire spread to the rooming house next door.

Firefighters were on the scene within minutes, but needed two-and-a-half hours to get the blaze under control.

Tenants from the second home affected were sheltered in a TTC bus that was taken to the scene.

The Fire Marshal's Office has been notified. The blaze is considered suspicious because no one was supposed to be inside the house at the time.

Damage is estimated at $700,000. There are no reports of injuries.

Anyone with information should call Crime Stoppers at (416) 222-TIPS.