Man under police guard after alleged arson

A Queensland man who allegedly set fire to a house in the state's southeast is now under police guard in hospital.

A 16-year-old girl suffered serious burns in the blaze and has been flown to Brisbane for treatment.

Police say seven people were inside the home at Oakhurst, near Maryborough, when it went up in flames on Sunday morning.

They all managed to flee before the home was gutted by fire.

Police allege a Dunmora man, 53, drove a prime-mover into the home, damaging two vehicles, before setting the house alight.

He is in Maryborough Hospital but is expected to be flown to Brisbane for burns treatment.