Police are hunting for an arsonist after a suspicious fire led to the rescue of a woman within a burning apartment building.

Emergency services were called to Percy St in West End, Townsville, after multiple units were found ablaze about 9pm on Thursday.

One unit was found fully engulfed in flames, which had spread to a second unit by the time officers arrived first on scene, police said.

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The officers heard a woman screaming, and found she was trapped inside the second unit.

Risking their own lives, the officers forced entry into the home to rescue her.

The 54-year-old woman was treated for smoke inhalation and taken to Townsville University Hospital in a stable condition.

Officers involved in the rescue were also treated for smoke inhalation, however, no one else was injured.

West End local Nakita Greatz spoke to 7NEWS and said she had been driving home from dinner when she saw the commotion.

“We pulled over to the side (of the road) and saw some smoke coming from the roof,” she said.

“Then we saw a silver car pull up, a man and a woman got out, obviously it was the homeowners.

“We heard that there was a dog caught in there, and the man dropped to the ground saying ‘no, please no’.”

Greatz said police pulled two dogs from the property and their condition is unknown.

A crime scene was declared and investigations into the cause of the fire are ongoing, police said.

Police are appealing for anyone with relevant information, CCTV or dashcam footage to come forward.