Police in Australia's Tasmania island said they will blow up a stash of chemicals seized from a residential property south of state capital Hobart during the weekend, amid concerns that the confiscated items could be used to make bombs.

"Nearby residents have been temporarily relocated until the scene is cleared as a precaution," Detective Acting Inspector Darren Latham from the state police said in a statement.

The public has been advised to avoid the area and a 28-year-old man is assisting police with their inquiries.

"Bomb-making instructions" were found with the chemicals, which were "in a quantity that caused some concern for us," local media quoted the inspector as saying.

Police acted on a tip-off and first went to the site late on Friday, where they have been watching the 28-year-old man for weeks, the ABC news channel reported.

The man does not have any known affiliations with any political or religious groups that would normally concern authorities, reported the news channel.