PRIME Minister Kevin Rudd says anyone found guilty of lighting the devastating Victorian bushfires should rot in jail. 

But he says that the facts will have to be established in any arson case before any punishment can take place.

Mr Rudd says the fire-ravaged townships will be rebuilt.

The PM spoke after toured some of the hardest-hit areas earlier over the past days and says he's taken away a sense of the trauma victims are feeling, but says there is also hope.

He says the extraordinary mentioning the courage by people, firefighters and neighbours and friends standing by putting their lives on the line.

AAP