Two women are fighting for life following a house fire authorities consider suspicious.

Detectives were investigating the cause of the Boxing Day blaze, which erupted shortly after 3am in Gulliver, a suburb of Townsville.

The pair, aged 53 and 83, were rushed to Townsville University Hospital with critical airway burns, while a third resident, a 55-year-old man, was taken to the same facility with non-life threatening injuries.

With a crime scene declared, investigators appealed to witnesses or anyone with CCTV or dashcam vision to come forward.

Neighbouring houses were evacuated in response to the heat generated by the fire.

A Queensland fire department spokesperson told local media the house was engulfed by flames, with crews still working to extinguish them four hours later.

“We had a house that was well involved [in the fire] when we arrived,” he told the Townsville Bulletin.

“We had four crews on scene.”