AFTERMATH: The remains of the Bridges Brothers building.
THE blaze that caused up to $10 million damage to Hobart's Bridges Brothers building was deliberately lit, Tasmania Police says.
Inspector David Plumpton said yesterday police were investigating the suspicious fire that started between midnight and 4am last Saturday.
"The Tasmanian Fire Service have concluded their investigation and identified the fire as being deliberately lit," Insp Plumpton said yesterday.
But he said it could still be some time before police charged anybody.
"We are undertaking a rigorous and detailed investigation, but it will take some time.
"We are still going through a lot of evidence and we want anyone who has any information or saw someone to contact police."
Meanwhile, Insp Plumpton said officers were still investigating a fire on Hobart's Queens Domain on Thursday night.
The blaze that destroyed 17ha of grass and bushland on the eastern side of the Domain also appeared to have been deliberately lit.
The fire continued to burn yesterday, preventing investigators from accessing the scene until late in the day.
It was initially estimated that the fire had burnt 5ha, but the full extent of destruction became apparent later.
Insp Plumpton said police believed the fire was deliberately lit because of the time it occurred and its location.
"But we will await final advice from the Tasmanian Fire Service," he said.
Fire Service officer Michael Netherton said a number of fires were still burning inside trees on the Domain, making the area unsafe.
But heavy showers yesterday helped fire officers and Hobart City Council crews douse parts of the fire in the morning.
"The rain had a significant impact on it but there are still a lot of fires inside trees," Mr Netherton said.
Investigations to determine the fire's cause were continuing.
-- with JENNIFER CRAWLEY