The number killed in Australias deadliest bushfires has now reached 200. And the death toll may still rise as police in the devastated southern state of Victoria as police continue their grim search for bodies in the ash and rubble of several razed towns. Australia has launched its biggest arson investigation into the fires, fanned by a heatwave and strong winds, which swept through towns north of Melbourne on February 7. "The toll has risen from 189 to 200," a police spokeswoman said, but declined to give any more detail of where bodies of more victims were found. Prime Minister Kevin Rudd has described the fires, with at least one deliberately lit, as "mass murder". A man - 39-year-old Brendan Sokaluk - has been charged with "arson causing death" over one of the deadly bushfires, which killed 21 people. In Victoria, arson carries a jail term of two to 15 years, and 25 years if there is loss of life.