A woman has been arrested for attempted murder and arson after two suspicious fires were lit at a Tokoroa house overnight.

A dog at the Kiwi Street house woke its occupants -- two adults and one teenager -- early this morning after the house was set ablaze.

The occupants attempted to put the fire out and called the Tokoroa Volunteer Fire Brigade.

Detective Sergeant Kevan Verry of Tokoroa police said if the dog had not woken the occupants, police would ``probably have been dealing with a multiple homicide'.

After a scene examination this morning, which found the fire was deliberate, police arrested a 42-year-old Tokoroa woman.

She was charged with attempted murder and two counts of arson and would appear in Tokoroa District Court tomorrow.